idnits 2.17.1 draft-ietf-calsch-ical-09.txt: -(2138): Line appears to be too long, but this could be caused by non-ascii characters in UTF-8 encoding -(3912): Line appears to be too long, but this could be caused by non-ascii characters in UTF-8 encoding -(4974): Line appears to be too long, but this could be caused by non-ascii characters in UTF-8 encoding -(5018): Line appears to be too long, but this could be caused by non-ascii characters in UTF-8 encoding -(5057): Line appears to be too long, but this could be caused by non-ascii characters in UTF-8 encoding -(6519): Line appears to be too long, but this could be caused by non-ascii characters in UTF-8 encoding Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** Looks like you're using RFC 2026 boilerplate. This must be updated to follow RFC 3978/3979, as updated by RFC 4748. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- ** Missing expiration date. The document expiration date should appear on the first and last page. ** The document seems to lack a 1id_guidelines paragraph about Internet-Drafts being working documents. ** The document seems to lack a 1id_guidelines paragraph about 6 months document validity -- however, there's a paragraph with a matching beginning. Boilerplate error? ** The document seems to lack a 1id_guidelines paragraph about the list of current Internet-Drafts. ** The document seems to lack a 1id_guidelines paragraph about the list of Shadow Directories. == Mismatching filename: the document gives the document name as 'draft-calsch-ical-09', but the file name used is 'draft-ietf-calsch-ical-09' == There are 9 instances of lines with non-ascii characters in the document. == No 'Intended status' indicated for this document; assuming Proposed Standard == The page length should not exceed 58 lines per page, but there was 133 longer pages, the longest (page 127) being 71 lines Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** The document seems to lack an IANA Considerations section. (See Section 2.2 of https://www.ietf.org/id-info/checklist for how to handle the case when there are no actions for IANA.) ** The document seems to lack an Authors' Addresses Section. ** The document seems to lack separate sections for Informative/Normative References. All references will be assumed normative when checking for downward references. ** There are 2108 instances of too long lines in the document, the longest one being 6 characters in excess of 72. ** The abstract seems to contain references ([ICMS], [RFC2048], [ITIP]), which it shouldn't. Please replace those with straight textual mentions of the documents in question. == There are 1 instance of lines with non-RFC2606-compliant FQDNs in the document. == There are 44 instances of lines with non-RFC6890-compliant IPv4 addresses in the document. If these are example addresses, they should be changed. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the RFC 3978 Section 5.4 Copyright Line does not match the current year == Line 2980 has weird spacing: '...he base offse...' == Line 3912 has weird spacing: '...ld this meeti...' == The document seems to lack the recommended RFC 2119 boilerplate, even if it appears to use RFC 2119 keywords -- however, there's a paragraph with a matching beginning. Boilerplate error? (The document does seem to have the reference to RFC 2119 which the ID-Checklist requires). == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'SHOULD not' in this paragraph: This property SHOULD not be used to alter the interpretation of an iCalendar object beyond the semantics specified in this memo. For example, it is not to be used to further the understanding of non-standard properties. == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'MUST not' in this paragraph: The property parameter CN is for the common or displayable name associated with the calendar address; ROLE, for the intended role that the attendee will have in the calendar component; PARTSTAT, for the status of the attendee�s participation; RSVP, for indicating whether the favor of a reply is requested; CUTYPE, to indicate the type of calendar user; MEMBER, to indicate the groups that the attendee belongs to; DELEGATED-TO, to indicate the calendar users that the original request was delegated to; and DELEGATED-FROM, to indicate whom the request was delegated from; SENT-BY, to indicate whom is acting on behalf of the ATTENDEE; and DIR, to indicate the URI that points to the directory information corresponding to the attendee. These property parameters can be specified on an "ATTENDEE" property in either a "VEVENT", "VTODO" or "VJOURNAL" calendar component. They MUST not be specified in an "ATTENDEE" property in a "VFREEBUSY" or "VALARM" calendar component. If the LANGUAGE property parameter is specified, the identified language applies to the CN parameter. == Couldn't figure out when the document was first submitted -- there may comments or warnings related to the use of a disclaimer for pre-RFC5378 work that could not be issued because of this. Please check the Legal Provisions document at https://trustee.ietf.org/license-info to determine if you need the pre-RFC5378 disclaimer. -- The document date (August 7, 1998) is 9393 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: 'ICAL' is mentioned on line 358, but not defined == Missing Reference: 'IRIP' is mentioned on line 532, but not defined == Missing Reference: 'MIME-DIR' is mentioned on line 5118, but not defined == Unused Reference: 'RFC 2047' is defined on line 7075, but no explicit reference was found in the text == Unused Reference: 'RFC 2111' is defined on line 7083, but no explicit reference was found in the text == Unused Reference: 'VCARD' is defined on line 7098, but no explicit reference was found in the text == Unused Reference: 'XAPIA' is defined on line 7106, but no explicit reference was found in the text -- Possible downref: Non-RFC (?) normative reference: ref. 'ICMS' -- Possible downref: Non-RFC (?) normative reference: ref. 'IMIP' -- Possible downref: Non-RFC (?) normative reference: ref. 'ITIP' -- Possible downref: Non-RFC (?) normative reference: ref. 'ISO 8601' -- Possible downref: Non-RFC (?) normative reference: ref. 'ISO 9070' -- Possible downref: Non-RFC (?) normative reference: ref. 'MIME DIR' ** Obsolete normative reference: RFC 822 (Obsoleted by RFC 2822) ** Obsolete normative reference: RFC 1738 (Obsoleted by RFC 4248, RFC 4266) ** Obsolete normative reference: RFC 1766 (Obsoleted by RFC 3066, RFC 3282) ** Obsolete normative reference: RFC 2048 (Obsoleted by RFC 4288, RFC 4289) ** Obsolete normative reference: RFC 2111 (Obsoleted by RFC 2392) ** Obsolete normative reference: RFC 2234 (Obsoleted by RFC 4234) ** Obsolete normative reference: RFC 2279 (Obsoleted by RFC 3629) -- Possible downref: Non-RFC (?) normative reference: ref. 'TZ' -- Possible downref: Non-RFC (?) normative reference: ref. 'VCARD' -- Possible downref: Non-RFC (?) normative reference: ref. 'VCAL' -- Possible downref: Non-RFC (?) normative reference: ref. 'XAPIA' Summary: 18 errors (**), 0 flaws (~~), 20 warnings (==), 11 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 Network Working Group Frank Dawson, Lotus 2 Internet Draft Derik Stenerson, Microsoft 3 4 Expires six months after: August 7, 1998 6 Internet Calendaring and Scheduling Core Object Specification 7 (iCalendar) 9 Status of this Memo 11 This memo is an Internet-Draft. Internet-Drafts are working documents 12 of the Internet Engineering Task Force (IETF), its areas, and its 13 working groups. Note that other groups can also distribute working 14 documents as Internet-Drafts. 16 Internet-Drafts are draft documents valid for a maximum of six 17 months. Internet-Drafts can be updated, replaced, or made obsolete by 18 other documents at any time. It is not appropriate to use Internet- 19 Drafts as reference material or to cite them other than as a "working 20 draft" or "work in progress". 22 To view the entire list of current Internet-Drafts, please check the 23 "1id-abstracts.txt" listing contained in the Internet-Drafts Shadow 24 Directories on ftp.is.co.za (Africa), ftp.nordu.net (Northern 25 Europe), ftp.nis.garr.it (Southern Europe), munnari.oz.au (Pacific 26 Rim), ftp.ietf.org (US East Coast), or ftp.isi.edu (US West Coast). 28 Distribution of this memo is unlimited. 30 Copyright (C) The Internet Society 1997. All Rights Reserved. 32 Abstract 34 There is a clear need to provide and deploy interoperable calendaring 35 and scheduling services for the Internet. Current group scheduling 36 and Personal Information Management (PIM) products are being extended 37 for use across the Internet, today, in proprietary ways. This memo 38 has been defined to provide the definition of a common format for 39 openly exchanging calendaring and scheduling information across the 40 Internet. 42 This memo is formatted as a registration for a MIME media type per 43 [RFC 2048]. However, the format in this memo is equally applicable 44 for use outside of a MIME message content type. 46 The proposed media type value is "text/calendar". This string would 47 label a media type containing calendaring and scheduling information 48 encoded as text characters formatted in a manner outlined below. 50 This MIME media type provides a standard content type for capturing 51 calendar event, to-do and journal entry information. It also can be 52 used to convey free/busy time information. The content type is 53 suitable as a MIME message entity that can be transferred over MIME 54 based email systems, using HTTP or some other Internet transport. In 56 Dawson/Stenerson 1 Expires February 1999 57 addition, the content type is useful as an object for interactions 58 between desktop applications using the operating system clipboard, 59 drag/drop or file systems capabilities. 61 This memo is based on the earlier work of the vCalendar specification 62 for the exchange of personal calendaring and scheduling information. 63 In order to avoid confusion with this referenced work, this memo is 64 to be known as the iCalendar specification. 66 Readers may also refer to the calendaring and scheduling model 67 defined in [ICMS] for a description of this Internet application. 69 This memo defines the format for specifying iCalendar object methods. 70 An iCalendar object method is a set of usage constraints for the 71 iCalendar object. For example, these methods might define scheduling 72 messages that request an event be scheduled, reply to an event 73 request, send a cancellation notice for an event, modify or replace 74 the definition of an event, provide a counter proposal for an 75 original event request, delegate an event request to another 76 individual, request free or busy time, reply to a free or busy time 77 request, or provide similar scheduling messages for a to-do or 78 journal entry calendar component. The iCalendar Transport-indendent 79 Interoperability Protocol (iTIP) defined in [ITIP] is one such 80 scheduling protocol. 82 Dawson/Stenerson 2 Expires February 1999 83 Table of Contents 85 1 Introduction.........................................................6 86 2 Basic Grammar and Conventions........................................6 87 2.1 Formatting Conventions...........................................7 88 2.2 Related Memos....................................................8 89 2.3 International Considerations.....................................8 90 3 Registration Information.............................................8 91 3.1 Content Type.....................................................9 92 3.2 Parameters.......................................................9 93 3.3 Content Header Fields...........................................10 94 3.4 Encoding Considerations.........................................10 95 3.5 Security Considerations.........................................10 96 3.6 Interoperability Considerations.................................11 97 3.7 Applications Which Use This Media Type..........................11 98 3.8 Additional Information..........................................11 99 3.9 Magic Numbers...................................................11 100 3.10 File Extensions................................................11 101 3.11 Contact for Further Information:...............................12 102 3.12 Intended Usage.................................................12 103 3.13 Authors/Change Controllers.....................................12 104 4 iCalendar Object Specification......................................12 105 4.1 Content Lines...................................................13 106 4.1.1 List and Field Separators....................................15 107 4.1.2 Multiple Values..............................................16 108 4.1.3 Binary Content...............................................16 109 4.1.4 Character Set................................................16 110 4.2 Property Parameters.............................................17 111 4.2.1 Alternate Text Representation................................18 112 4.2.2 Common Name..................................................18 113 4.2.3 Calendar User Type...........................................19 114 4.2.4 Delegators...................................................19 115 4.2.5 Delegatees...................................................20 116 4.2.6 Directory Entry Reference....................................20 117 4.2.7 Inline Encoding..............................................21 118 4.2.8 Format Type..................................................21 119 4.2.9 Free/Busy Time Type..........................................22 120 4.2.10 Language....................................................22 121 4.2.11 Group or List Membership....................................23 122 4.2.12 Participation Status........................................24 123 4.2.13 Recurrence Identifier Range.................................25 124 4.2.14 Alarm Trigger Relationship..................................26 125 4.2.15 Relationship Type...........................................26 126 4.2.16 Participation Role..........................................27 127 4.2.17 RSVP Expectation............................................27 128 4.2.18 Sent By.....................................................28 129 4.2.19 Time Zone Identifier........................................28 130 4.2.20 Value Data Types............................................29 131 4.3 Property Value Data Types.......................................30 132 4.3.1 Binary.......................................................30 133 4.3.2 Boolean......................................................31 134 4.3.3 Calendar User Address........................................31 136 Dawson/Stenerson 3 Expires February 1999 137 4.3.4 Date.........................................................32 138 4.3.5 Date-Time....................................................32 139 4.3.6 Duration.....................................................34 140 4.3.7 Float........................................................35 141 4.3.8 Integer......................................................35 142 4.3.9 Period of Time...............................................36 143 4.3.10 Recurrence Rule.............................................37 144 4.3.11 Text........................................................42 145 4.3.12 Time........................................................43 146 4.3.13 URI.........................................................45 147 4.3.14 UTC Offset..................................................45 148 4.4 iCalendar Object................................................46 149 4.5 Property........................................................46 150 4.6 Calendar Components.............................................47 151 4.6.1 Event Component..............................................48 152 4.6.2 To-do Component..............................................50 153 4.6.3 Journal Component............................................51 154 4.6.4 Free/Busy Component..........................................53 155 4.6.5 Time Zone Component..........................................55 156 4.6.6 Alarm Component..............................................61 157 4.7 Calendar Properties.............................................67 158 4.7.1 Calendar Scale...............................................67 159 4.7.2 Method.......................................................67 160 4.7.3 Product Identifier...........................................68 161 4.7.4 Version......................................................69 162 4.8 Component Properties............................................70 163 4.8.1 Descriptive Component Properties.............................70 164 4.8.1.1 Attachment...............................................70 165 4.8.1.2 Categories...............................................71 166 4.8.1.3 Classification...........................................72 167 4.8.1.4 Comment..................................................72 168 4.8.1.5 Description..............................................73 169 4.8.1.6 Geographic Position......................................74 170 4.8.1.7 Location.................................................76 171 4.8.1.8 Percent Complete.........................................77 172 4.8.1.9 Priority.................................................77 173 4.8.1.10 Resources...............................................79 174 4.8.1.11 Status..................................................80 175 4.8.1.12 Summary.................................................81 176 4.8.2 Date and Time Component Properties...........................82 177 4.8.2.1 Date/Time Completed......................................82 178 4.8.2.2 Date/Time End............................................82 179 4.8.2.3 Date/Time Due............................................83 180 4.8.2.4 Date/Time Start..........................................84 181 4.8.2.5 Duration.................................................85 182 4.8.2.6 Free/Busy Time...........................................86 183 4.8.2.7 Time Transparency........................................87 184 4.8.3 Time Zone Component Properties...............................88 185 4.8.3.1 Time Zone Identifier.....................................88 186 4.8.3.2 Time Zone Name...........................................89 187 4.8.3.3 Time Zone Offset From....................................90 188 4.8.3.4 Time Zone Offset To......................................91 189 4.8.3.5 Time Zone URL............................................91 190 4.8.4 Relationship Component Properties............................92 192 Dawson/Stenerson 4 Expires February 1999 193 4.8.4.1 Attendee.................................................92 194 4.8.4.2 Contact..................................................94 195 4.8.4.3 Organizer................................................96 196 4.8.4.4 Recurrence ID............................................97 197 4.8.4.5 Related To...............................................98 198 4.8.4.6 Uniform Resource Locator................................100 199 4.8.4.7 Unique Identifier.......................................100 200 4.8.5 Recurrence Component Properties.............................102 201 4.8.5.1 Exception Date/Times....................................102 202 4.8.5.2 Exception Rule..........................................103 203 4.8.5.3 Recurrence Date/Times...................................104 204 4.8.5.4 Recurrence Rule.........................................105 205 4.8.6 Alarm Component Properties..................................113 206 4.8.6.1 Action..................................................113 207 4.8.6.2 Repeat Count............................................114 208 4.8.6.3 Trigger.................................................115 209 4.8.7 Change Management Component Properties......................117 210 4.8.7.1 Date/Time Created.......................................117 211 4.8.7.2 Date/Time Stamp.........................................117 212 4.8.7.3 Last Modified...........................................118 213 4.8.7.4 Sequence Number.........................................119 214 4.8.8 Miscellaneous Component Properties..........................120 215 4.8.8.1 Non-standard Properties.................................120 216 4.8.8.2 Request Status..........................................121 217 5 iCalendar Object Examples..........................................123 218 6 Recommended Practices..............................................126 219 7 Registration of Content Type Elements..............................128 220 7.1 Registration of New and Modified iCalendar Object Methods......128 221 7.2 Registration of New Properties.................................128 222 7.2.1 Define the property.........................................128 223 7.2.2 Post the Property definition................................129 224 7.2.3 Allow a comment period......................................129 225 7.2.4 Submit the property for approval............................129 226 7.3 Property Change Control........................................130 227 8 References.........................................................130 228 9 Acknowledgments....................................................132 229 10 Author's Address..................................................132 230 11 Full Copyright Statement..........................................133 232 Dawson/Stenerson 5 Expires February 1999 233 1 Introduction 235 The use of calendaring and scheduling has grown considerably in the 236 last decade. Enterprise and inter-enterprise business has become 237 dependent on rapid scheduling of events and actions using this 238 information technology. However, the longer term growth of 239 calendaring and scheduling, is currently limited by the lack of 240 Internet standards for the message content types that are central to 241 these knowledgeware applications. This memo is intended to progress 242 the level of interoperability possible between dissimilar calendaring 243 and scheduling applications. This memo defines a MIME content type 244 for exchanging electronic calendaring and scheduling information. The 245 Internet Calendaring and Scheduling Core Object Specification, or 246 iCalendar, allows for the capture and exchange of information 247 normally stored within a calendaring and scheduling application; such 248 as a Personal Information Manager (PIM) or a Group Scheduling 249 product. 251 The calendaring and scheduling model, defined in the [ICMS], is a 252 useful reference to terms and the general framework of this Internet 253 application. 255 The iCalendar format is suitable as an exchange format between 256 applications or systems. The format is defined in terms of a MIME 257 content type. This will enable the object to be exchanged using 258 several transports, including but not limited to SMTP, HTTP, a file 259 system, desktop interactive protocols such as the use of a memory- 260 based clipboard or drag/drop interactions, point-to-point 261 asynchronous communication, wired-network transport, or some form of 262 unwired transport such as infrared might also be used. 264 The memo also provides for the definition of iCalendar object methods 265 that will map this content type to a set of messages for supporting 266 calendaring and scheduling operations such as requesting, replying 267 to, modifying, and canceling meetings or appointments, to-dos and 268 journal entries. The iCalendar object methods can be used to define 269 other calendaring and scheduling operations such a requesting for and 270 replying with free/busy time data. Such a scheduling protocol is 271 defined in the iCalendar Transport-independent Interoperability 272 Protocol (iTIP) defined in [ITIP]. 274 The memo also includes a formal grammar for the content type based on 275 the Internet ABNF defined in [RFC 2234]. This ABNF is required for 276 the implementation of parsers and to serve as the definitive 277 reference when ambiguities or questions arise in interpreting the 278 descriptive prose definition of the memo. 280 2 Basic Grammar and Conventions 282 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 283 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY" and 285 Dawson/Stenerson 6 Expires February 1999 286 "OPTIONAL" in this document are to be interoperated as described in 287 [RFC 2119]. 289 This memo makes use of both a descriptive prose and a more formal 290 notation for defining the calendaring and scheduling format. 292 The notation used in this memo is the ABNF notation of [RFC 2234]. 293 Readers intending on implementing this format defined in this memo 294 should be familiar with this notation in order to properly interpret 295 the specifications of this memo. 297 All numeric and hexadecimal values used in this memo are given in 298 decimal notation. 300 All names of properties, property parameters, enumerated property 301 values and property parameter values are case-insensitive. However, 302 all other property values are case-sensitive, unless otherwise 303 stated. 305 Note: All indented editorial notes, such as this one, are 306 intended to provide the reader with additional information. The 307 information is not essential to the building of an 308 implementation conformant with this memo. The information is 309 provided to highlight a particular feature or characteristic of 310 the memo. 312 The format for the iCalendar object is based on the syntax of the 313 [MIME DIR] content type. While the iCalendar object is not a profile 314 of the [MIME DIR] content type, it does reuse a number of the 315 elements from the [MIME DIR] specification. 317 2.1 Formatting Conventions 319 The mechanisms defined in this memo are defined in prose. Many of the 320 terms used to describe these have common usage that is different than 321 the standards usage of this memo. In order to reference within this 322 memo elements of the calendaring and scheduling model [ICMS], core 323 object (this memo) or interoperability protocol [ITIP] some 324 formatting conventions have been used. Calendaring and scheduling 325 roles defined by [ICMS] are referred to in quoted-strings of text 326 with the first character of each word in upper case. For example, 327 "Organizer" refers to a role of a "Calendar User" within the 328 scheduling protocol defined by [ITIP]. Calendar components defined by 329 this memo are referred to with capitalized, quoted-strings of text. 330 All calendar components start with the letter "V". For example, 331 "VEVENT" refers to the event calendar component, "VTODO" refers to 332 the to-do calendar component and "VJOURNAL" refers to the daily 333 journal calendar component. Scheduling methods defined by [ITIP] are 334 referred to with capitalized, quoted-strings of text. For example, 335 "REQUEST" refers to the method for requesting a scheduling calendar 336 component be created or modified, "REPLY" refers to the method a 337 recipient of a request uses to update their status with the 338 "Organizer" of the calendar component. 340 Dawson/Stenerson 7 Expires February 1999 341 The properties defined by this memo are referred to with capitalized, 342 quoted-strings of text, followed by the word "property". For example, 343 "ATTENDEE" property refers to the iCalendar property used to convey 344 the calendar address of a calendar user. Property parameters defined 345 by this memo are referred to with lowercase, quoted-strings of text, 346 followed by the word "parameter". For example, "value" parameter 347 refers to the iCalendar property parameter used to override the 348 default data type for a property value. Enumerated values defined by 349 this memo are referred to with capitalized text, either alone or 350 followed by the word "value". For example, the "MINUTELY" value can 351 be used with the "FREQ" component of the "RECUR" data type to specify 352 repeating components based on an interval of one minute or more. 354 2.2 Related Memos 356 Implementers will need to be familiar with several other memos that, 357 along with this memo, form a framework for Internet calendaring and 358 scheduling standards. This memo, [ICAL], specifies a core 359 specification of objects, data types, properties and property 360 parameters. 362 [ICMS] - specifies a common terminology and abstract model; 364 [ITIP] - specifies an interoperability protocol for scheduling 365 between different implementations; 367 [IMIP] specifies an Internet email binding for [ITIP]. 369 [IRIP] - specifies an Internet real time protocol binding for [ITIP]. 371 This memo does not attempt to repeat the specification of concepts or 372 definitions from these other memos. Where possible, references are 373 made to the memo that provides for the specification of these 374 concepts or definitions. 376 2.3 International Considerations 378 In the rest of this document, descriptions of characters are of the 379 form "character name (codepoint)", where "codepoint" is from the US- 380 ASCII character set. The "character name" is the authoritative 381 description; (codepoint) is a reference to that character in US- 382 ASCII or US-ASCII compatible sets (for example the ISO-8859-x family, 383 UTF-8, ISO-2022-xx, KOI8-R). If a non-US-ASCII compatible character 384 set is used, appropriate code-point from that character set MUST be 385 chosen instead. Use of non-US-ASCII-compatible character sets is NOT 386 recommended. 388 3 Registration Information 390 The Calendaring and Scheduling Core Object Specification is intended 391 for use as a MIME content type. However, the implementation of the 392 memo is in no way limited solely as a MIME content type. 394 Dawson/Stenerson 8 Expires February 1999 395 3.1 Content Type 397 The following text is intended to register this memo as the MIME 398 content type "text/calendar". 400 To: ietf-types@uninett.no 402 Subject: Registration of MIME content type text/calendar. 404 MIME media type name: text 406 MIME subtype name: calendar 408 3.2 Parameters 410 Required parameters: none 412 Optional parameters: charset, method, component and optinfo 414 The "charset" parameter is defined in [RFC 2046] for other body 415 parts. It is used to identify the default character set used within 416 the body part. 418 The "method" parameter is used to convey the iCalendar object method 419 or transaction semantics for the calendaring and scheduling 420 information. It also is an identifier for the restricted set of 421 properties and values that the iCalendar object consists of. The 422 parameter is to be used as a guide for applications interpreting the 423 information contained within the body part. It SHOULD NOT be used to 424 exclude or require particular pieces of information unless the 425 identified method definition specifically calls for this behavior. 426 Unless specifically forbidden by a particular method definition, a 427 text/calendar content type can contain any set of properties 428 permitted by the Calendaring and Scheduling Core Object 429 Specification. The "method" parameter MUST be the same value as that 430 specified in the "METHOD" component property in the iCalendar object. 431 If one is present, the other MUST also be present. 433 The value for the "method" parameter is defined as follows: 435 method = 1*(ALPHA / DIGIT / "-") 436 ; IANA registered iCalendar object method 438 The "component" parameter conveys the type of iCalendar calendar 439 component within the body part. If the iCalendar object contains more 440 than one calendar component type, then multiple component parameters 441 MUST be specified. 443 The value for the "component" parameter is defined as follows: 445 component = ("VEVENT" / "VTODO" / "VJOURNAL" / "VFREEBUSY" 446 / "VTIMEZONE" / x-name / iana-token) 448 Dawson/Stenerson 9 Expires February 1999 449 The "optinfo" parameter conveys optional information about the 450 iCalendar object within the body part. This parameter can only 451 specify semantics already specified by the iCalendar object and that 452 can be otherwise determined by parsing the body part. In addition, 453 the optional information specified by this parameter MUST be 454 consistent with that information specified by the iCalendar object. 455 For example, it can be used to convey the "Attendee" response status 456 to a meeting request. The parameter value consists of a string value. 457 The parameter can be specified multiple times. 459 This parameter MAY only specify semantics already specified by the 460 iCalendar object and that can be otherwise determined by parsing the 461 body part. 463 The value for the "optinfo" parameter is defined as follows: 465 optinfo = infovalue / qinfovalue 467 infovalue = iana-token / x-name 469 qinfovalue = DQUOTE (infovalue) DQUOTE 471 3.3 Content Header Fields 473 Optional content header fields: Any header fields defined by [RFC 474 2045]. 476 3.4 Encoding Considerations 478 This MIME content type can contain 8bit characters, so the use of 479 quoted-printable or BASE64 MIME content-transfer-encodings might be 480 necessary when iCalendar objects are transferred across protocols 481 restricted to the 7bit repertoire. Note that a text valued property 482 in the content entity can also have content encoding of special 483 characters using a BACKSLASH character (US-ASCII decimal 92) 484 escapement technique. This means that content values can end up 485 encoded twice. 487 3.5 Security Considerations 489 SPOOFING - - In this memo, the "Organizer" is the only person 490 authorized to make changes to an existing "VEVENT", "VTODO", 491 "VJOURNAL" calendar component and redistribute the updates to the 492 "Attendees". An iCalendar object that maliciously changes or cancels 493 an existing "VEVENT", "VTODO" or "VJOURNAL" or "VFREEBUSY" calendar 494 component might be constructed by someone other than the "Organizer" 495 and sent to the "Attendees". In addition in this memo, other than the 496 "Organizer", an "Attendee" of a "VEVENT", "VTODO", "VJOURNAL" 497 calendar component is the only other person authorized to update any 498 parameter associated with their "ATTENDEE" property and send it to 499 the "Organizer". An iCalendar object that maliciously changes the 500 "ATTENDEE" parameters can be constructed by someone other than the 501 real "Attendee" and sent to the "Organizer". 503 Dawson/Stenerson 10 Expires February 1999 504 PROCEDURAL ALARMS - - An iCalendar object can be created that 505 contains a "VEVENT" and "VTODO" calendar component with "VALARM" 506 calendar components. The "VALARM" calendar component can be of type 507 PROCEDURE and can have an attachment containing some sort of 508 executable program. Implementations that incorporate these types of 509 alarms are subject to any virus or malicious attack that might occur 510 as a result of executing the attachment. 512 ATTACHMENTS - - An iCalendar object can include references to Uniform 513 Resource Locators that can be programmed resources. 515 Implementers and users of this memo should be aware of the network 516 security implications of accepting and parsing such information. In 517 addition, the security considerations observed by implementations of 518 electronic mail systems should be followed for this memo. 520 3.6 Interoperability Considerations 522 This MIME content type is intended to define a common format for 523 conveying calendaring and scheduling information between different 524 systems. It is heavily based on the earlier [VCAL] industry 525 specification. 527 3.7 Applications Which Use This Media Type 529 This content-type is designed for widespread use by Internet 530 calendaring and scheduling applications. In addition, applications in 531 the workflow and document management area might find this content- 532 type applicable. The [ITIP] and [IMIP] and [IRIP] Internet protocols 533 directly use this content-type also. Future work on an Internet 534 calendar access protocol will utilize this content-type too. 536 3.8 Additional Information 538 This memo defines this content-type. 540 3.9 Magic Numbers 542 None. 544 3.10 File Extensions 546 The file extension of "ics" is to be used to designate a file 547 containing (an arbitrary set of) calendaring and scheduling 548 information consistent with this MIME content type. 550 The file extension of "ifb" is to be used to designate a file 551 containing free or busy time information consistent with this MIME 552 content type. 554 Macintosh file type codes: The file type code of "iCal" is to be used 555 in Apple MacIntosh operating system environments to designate a file 557 Dawson/Stenerson 11 Expires February 1999 558 containing calendaring and scheduling information consistent with 559 this MIME media type. 561 The file type code of "iFBf" is to be used in Apple MacIntosh 562 operating system environments to designate a file containing free or 563 busy time information consistent with this MIME media type. 565 3.11 Contact for Further Information: 567 Frank Dawson 568 6544 Battleford Drive 569 Raleigh, NC 27613-3502 570 919-676-9515 (Telephone) 571 919-676-9564 (Data/Facsimile) 572 Frank_Dawson@Lotus.com (Internet Mail) 574 Derik Stenerson 575 One Microsoft Way 576 Redmond, WA 98052-6399 577 425-936-5522 (Telephone) 578 425-936-7329 (Facsimile) 579 deriks@microsoft.com (Internet Mail) 581 3.12 Intended Usage 583 COMMON 585 3.13 Authors/Change Controllers 587 Frank Dawson 588 6544 Battleford Drive 589 Raleigh, NC 27613-3502 590 919-676-9515 (Telephone) 591 919-676-9564 (Data/Facsimile) 592 Frank_Dawson@Lotus.com (Internet Mail) 594 Derik Stenerson 595 One Microsoft Way 596 Redmond, WA 98052-6399 597 425-936-5522 (Telephone) 598 425-936-7329 (Facsimile) 599 deriks@microsoft.com (Internet Mail) 601 4 iCalendar Object Specification 603 The following sections define the details of a Calendaring and 604 Scheduling Core Object Specification. This information is intended to 605 be an integral part of the MIME content type registration. In 606 addition, this information can be used independent of such content 607 registration. In particular, this memo has direct applicability for 608 use as a calendaring and scheduling exchange format in file-, memory- 609 or network-based transport mechanisms. 611 Dawson/Stenerson 12 Expires February 1999 612 4.1 Content Lines 614 The iCalendar object is organized into individual lines of text, 615 called content lines. Content lines are delimited by a line break, 616 which is a CRLF sequence (US-ASCII decimal 13, followed by US-ASCII 617 decimal 10). 619 Lines of text SHOULD NOT be longer than 75 octets, excluding the line 620 break. Long content lines SHOULD be split into a multiple line 621 representations using a line "folding" technique. That is, a long 622 line can be split between any two characters by inserting a CRLF 623 immediately followed by a single linear white space character (i.e., 624 SPACE, US-ASCII decimal 32 or HTAB, US-ASCII decimal 9). Any sequence 625 of CRLF followed immediately by a single linear white space character 626 is ignored (i.e., removed) when processing the content type. 628 For example the line: 630 DESCRIPTION:This is a long description that exists on a long line. 632 Can be represented as: 634 DESCRIPTION:This is a lo 635 ng description 636 that exists on a long line. 638 The process of moving from this folded multiple line representation 639 to its single line representation is called "unfolding". Unfolding is 640 accomplished by removing the CRLF character and the linear white 641 space character that immediately follows. 643 When parsing a content line, folded lines MUST first be unfolded 644 according to the unfolding procedure described above. When generating 645 a content line, lines longer than 75 octets SHOULD be folded 646 according to the folding procedure described above. 648 The content information associated with an iCalendar object is 649 formatted using a syntax similar to that defined by [MIME DIR]. That 650 is, the content information consists of CRLF-separated content lines. 652 The following notation defines the lines of content in an iCalendar 653 object: 655 contentline = name *(";" param ) ":" value CRLF 656 ; This ABNF is just a general definition for an initial parsing 657 ; of the content line into its property name, parameter list, 658 ; and value string 660 ; When parsing a content line, folded lines MUST first 661 ; be unfolded according to the unfolding procedure 662 ; described above. When generating a content line, lines 663 ; longer than 75 octets SHOULD be folded according to 664 ; the folding procedure described above. 666 Dawson/Stenerson 13 Expires February 1999 667 name = x-name / iana-token 669 iana-token = 1*(ALPHA / DIGIT / "-") 670 ; iCalendar identifier registered with IANA 672 x-name = "X-" [vendorid "-"] 1*(ALPHA / DIGIT / "-") 673 ; Reservered for experimental use. Not intended for use in 674 ; released products. 676 vendorid = 3*(ALPHA / DIGIT) ;Vendor identification 678 param = param-name "=" param-value 679 *("," param-value) 680 ; Each property defines the specific ABNF for the parameters 681 ; allowed on the property. Refer to specific properties for 682 ; precise parameter ABNF. 684 param-name = iana-token / x-token 686 param-value = paramtext / quoted-string 688 paramtext = *SAFE-CHAR 690 value = *VALUE-CHAR 692 quoted-string = DQUOTE *QSAFE-CHAR DQUOTE 694 NON-US-ASCII = %x80-F8 695 ; Use restricted by charset parameter 696 ; on outer MIME object (UTF-8 preferred) 698 QSAFE-CHAR = WSP / %x21 / %x23-7E / NON-US-ASCII 699 ; Any character except CTLs and DQUOTE 701 SAFE-CHAR = WSP / %x21 / %x23-2B / %x2D-39 / %x3C-7E 702 / NON-US-ASCII 703 ; Any character except CTLs, DQUOTE, ";", ":", "," 705 VALUE-CHAR = WSP / %x21-7E / NON-US-ASCII 706 ; Any textual character 708 CR = %x0D 709 ; carriage return 711 LF = %x0A 712 ; line feed 714 CRLF = CR LF 715 ; Internet standard newline 717 CTL = %x00-08 / %x0A-1F / %x7F 718 ; Controls 720 ALPHA = %x41-5A / %x61-7A ; A-Z / a-z 722 Dawson/Stenerson 14 Expires February 1999 723 DIGIT = %x30-39 724 ; 0-9 726 DQUOTE = %x22 727 ; Quotation Mark 729 WSP = SPACE / HTAB 731 SPACE = %x20 733 HTAB = %x09 735 The property value component of a content line has a format that is 736 property specific. Refer to the section describing each property for 737 a definition of this format. 739 All names of properties, property parameters, enumerated property 740 values and property parameter values are case-insensitive. However, 741 all other property values are case-sensitive, unless otherwise 742 stated. 744 4.1.1 List and Field Separators 746 Some properties and parameters allow a list of values. Values in a 747 list of values MUST be separated by a COMMA character (US-ASCII 748 decimal 44). There is no significance to the order of values in a 749 list. For those parameter values (such as those that specify URI 750 values) that are specified in quoted-strings, the individual quoted- 751 strings are separated by a COMMA character (US-ASCII decimal 44). 753 Some property values are defined in terms of multiple parts. These 754 structured property values MUST have their value parts separated by a 755 SEMICOLON character (US-ASCII decimal 59). 757 Some properties allow a list of parameters. Each property parameter 758 in a list of property parameters MUST be separated by a SEMICOLON 759 character (US-ASCII decimal 59). 761 Property parameters with values containing a COLON, a SEMICOLON or a 762 COMMA character MUST be placed in quoted text. 764 For example, in the following properties a SEMICOLON is used to 765 separate property parameters from each other, and a COMMA is used to 766 separate property values in a value list. 768 ATTENDEE;RSVP=TRUE;ROLE=REQ-PARTICIPANT:MAILTO: 769 jsmith@host.com 771 RDATE;VALUE=DATE:19970304,19970504,19970704,19970904 773 Dawson/Stenerson 15 Expires February 1999 774 4.1.2 Multiple Values 776 Some properties defined in the iCalendar object can have multiple 777 values. The general rule for encoding multi-valued items is to simply 778 create a new content line for each value, including the property 779 name. However, it should be noted that some properties support 780 encoding multiple values in a single property by separating the 781 values with a COMMA character (US-ASCII decimal 44). Individual 782 property definitions should be consulted for determining whether a 783 specific property allows multiple values and in which of these two 784 forms. 786 4.1.3 Binary Content 788 Binary content information in an iCalendar object SHOULD be 789 referenced using a URI within a property value. That is the binary 790 content information SHOULD be placed in an external MIME entity that 791 can be referenced by a URI from within the iCalendar object. In 792 applications where this is not feasible, binary content information 793 can be included within an iCalendar object, but only after first 794 encoding it into text using the "BASE64" encoding method defined in 795 [RFC 2045]. Inline binary contact SHOULD only be used in applications 796 whose special circumstances demand that an iCalendar object be 797 expressed as a single entity. A property containing inline binary 798 content information MUST specify the "ENCODING" property parameter. 799 Binary content information placed external to the iCalendar object 800 MUST be referenced by a uniform resource identifier (URI). 802 The following example specifies an "ATTACH" property that references 803 an attachment external to the iCalendar object with a URI reference: 805 ATTACH:http://xyz.com/public/quarterly-report.doc 807 The following example specifies an "ATTACH" property with inline 808 binary encoded content information: 810 ATTACH;FMTTYPE=image/basic;ENCODING=BASE64;VALUE=BINARY: 811 MIICajCCAdOgAwIBAgICBEUwDQYJKoZIhvcNAQEEBQAwdzELMAkGA1U 812 EBhMCVVMxLDAqBgNVBAoTI05ldHNjYXBlIENvbW11bmljYXRpb25zIE 813 <...remainder of "BASE64" encoded binary data...> 815 4.1.4 Character Set 817 There is not a property parameter to declare the character set used 818 in a property value. The default character set for an iCalendar 819 object is UTF-8 as defined in [RFC 2279]. 821 The "charset" Content-Type parameter can be used in MIME transports 822 to specify any other IANA registered character set. 824 Dawson/Stenerson 16 Expires February 1999 825 4.2 Property Parameters 827 A property can have attributes associated with it. These "property 828 parameters" contain meta-information about the property or the 829 property value. Property parameters are provided to specify such 830 information as the location of an alternate text representation for a 831 property value, the language of a text property value, the data type 832 of the property value and other attributes. 834 Property parameter values that contain the COLON (US-ASCII decimal 835 58), SEMICOLON (US-ASCII decimal 59) or COMMA (US-ASCII decimal 44) 836 character separators MUST be specified as quoted-string text values. 837 Property parameter values MUST NOT contain the DOUBLE-QUOTE (US-ASCII 838 decimal 22) character. The DOUBLE-QUOTE (US-ASCII decimal 22) 839 character is used as a delimiter for parameter values that contain 840 restricted characters or URI text. For example: 842 DESCRIPTION;ALTREP="http://www.wiz.org":The Fall'98 Wild Wizards 843 Conference - - Las Vegas, NV, USA 845 Property parameter values that are not in quoted strings are case 846 insensitive. 848 The general property parameters defined by this memo are defined by 849 the following notation: 851 parameter = altrepparam ; Alternate text representation 852 / cnparam ; Common name 853 / cutypeparam ; Calendar user type 854 / delfromparam ; Delegator 855 / deltoparam ; Delegatee 856 / dirparam ; Directory entry 857 / encodingparam ; Inline encoding 858 / fmttypeparam ; Format type 859 / fbtypeparam ; Free/busy time type 860 / languageparam ; Language for text 861 / memberparam ; Group or list membership 862 / partstatparam ; Participation status 863 / rangeparam ; Recurrence identifier range 864 / trigrelparam ; Alarm trigger relationship 865 / reltypeparam ; Relationship type 866 / roleparam ; Participation role 867 / rsvpparam ; RSVP expectation 868 / sentbyparam ; Sent by 869 / tzidparam ; Reference to time zone object 870 / valuetypeparam ; Property value data type 871 / ianaparam 872 ; Some other IANA registered iCalendar parameter. 873 / xparam 874 ; A non-standard, experimental parameter. 876 ianaparam = iana-token "=" param-value *("," param-value) 878 Dawson/Stenerson 17 Expires February 1999 879 xparam =x-name "=" param-value *("," param-value) 881 4.2.1 Alternate Text Representation 883 Parameter Name: ALTREP 885 Purpose: To specify an alternate text representation for the property 886 value. 888 Format Definition: The property parameter is defined by the following 889 notation: 891 altrepparam = "ALTREP" "=" DQUOTE uri DQUOTE 893 Description: The parameter specifies a URI that points to an 894 alternate representation for a textual property value. A property 895 specifying this parameter MUST also include a value that reflects the 896 default representation of the text value. The individual URI 897 parameter values MUST each be specified in a quoted-string. 899 Example: 901 DESCRIPTION;ALTREP="CID:":Project 902 XYZ Review Meeting will include the following agenda items: (a) 903 Market Overview, (b) Finances, (c) Project Management 905 The "ALTREP" property parameter value might point to a "text/html" 906 content portion. 908 Content-Type:text/html 909 Content-Id: 911 912

Project XYZ Review Meeting will include the following 913 agenda items:

  1. Market 914 Overview
  2. Finances
  3. Project Management

915 917 4.2.2 Common Name 919 Parameter Name: CN 921 Purpose: To specify the common name to be associated with the 922 calendar user specified by the property. 924 Format Definition: The property parameter is defined by the following 925 notation: 927 cnparam = "CN" "=" param-value 929 Description: This parameter can be specified on properties with a 930 CAL-ADDRESS value type. The parameter specifies the common name to be 931 associated with the calendar user specified by the property. The 933 Dawson/Stenerson 18 Expires February 1999 934 parameter value is text. The parameter value can be used for display 935 text to be associated with the calendar address specified by the 936 property. 938 Example: 940 ORGANIZER;CN="John Smith":MAILTO:jsmith@host.com 942 4.2.3 Calendar User Type 944 Parameter Name: CUTYPE 946 Purpose: To specify the type of calendar user specified by the 947 property. 949 Format Definition: The property parameter is defined by the following 950 notation: 952 cutypeparam = "CUTYPE" "=" 953 ("INDIVIDUAL" ; An individual 954 / "GROUP" ; A group of individuals 955 / "RESOURCE" ; A physical resource 956 / "ROOM" ; A room resource 957 / "UNKNOWN" ; Otherwise not known 958 / x-name ; Experimental type 959 / iana-token) ; Other IANA registered 960 ; type 961 ; Default is INDIVIDUAL 963 Description: This parameter can be specified on properties with a 964 CAL-ADDRESS value type. The parameter identifies the type of calendar 965 user specified by the property. If not specified on a property that 966 allows this parameter, the default is INDIVIDUAL. 968 Example: 970 ATTENDEE;CUTYPE=GROUP:MAILTO:ietf-calsch@imc.org 972 4.2.4 Delegators 974 Parameter Name: DELEGATED-FROM 976 Purpose: To specify the calendar users that have delegated their 977 participation to the calendar user specified by the property. 979 Format Definition: The property parameter is defined by the following 980 notation: 982 delfromparam = "DELEGATED-FROM" "=" DQUOTE cal-address DQUOTE 983 *("," DQUOTE cal-address DQUOTE) 985 Description: This parameter can be specified on properties with a 986 CAL-ADDRESS value type. This parameter can be specified on a property 988 Dawson/Stenerson 19 Expires February 1999 989 that has a value type of calendar address. This parameter specifies 990 those calendar uses that have delegated their participation in a 991 group scheduled event or to-do to the calendar user specified by the 992 property. The value MUST be a MAILTO URI as defined in [RFC 1738]. 993 The individual calendar address parameter values MUST each be 994 specified in a quoted-string. 996 Example: 998 ATTENDEE;DELEGATED-FROM="MAILTO:jsmith@host.com":MAILTO: 999 jdoe@host.com 1001 4.2.5 Delegatees 1003 Parameter Name: DELEGATED-TO 1005 Purpose: To specify the calendar users to whom the calendar user 1006 specified by the property has delegated participation. 1008 Format Definition: The property parameter is defined by the following 1009 notation: 1011 deltoparam = "DELEGATED-TO" "=" DQUOTE cal-address DQUOTE 1012 *("," DQUOTE cal-address DQUOTE) 1014 Description: This parameter can be specified on properties with a 1015 CAL-ADDRESS value type. This parameter specifies those calendar users 1016 whom have been delegated participation in a group scheduled event or 1017 to-do by the calendar user specified by the property. The value MUST 1018 be a MAILTO URI as defined in [RFC 1738]. The individual calendar 1019 address parameter values MUST each be specified in a quoted-string. 1021 Example: 1023 ATTENDEE;DELEGATED-TO="MAILTO:jdoe@host.com","MAILTO:jqpublic@ 1024 host.com":MAILTO:jsmith@host.com 1026 4.2.6 Directory Entry Reference 1028 Parameter Name: DIR 1030 Purpose: To specify reference to a directory entry associated with 1031 the calendar user specified by the property. 1033 Format Definition: The property parameter is defined by the following 1034 notation: 1036 dirparam = "DIR" "=" DQUOTE uri DQUOTE 1038 Description: This parameter can be specified on properties with a 1039 CAL-ADDRESS value type. The parameter specifies a reference to the 1040 directory entry associated with the calendar user specified by the 1042 Dawson/Stenerson 20 Expires February 1999 1043 property. The parameter value is a URI. The individual URI parameter 1044 values MUST each be specified in a quoted-string. 1046 Example: 1048 ORGANIZER;DIR="ldap://host.com:6666/o=eDABC%20Industries,c=3DUS?? 1049 (cn=3DBJim%20Dolittle)":MAILTO:jimdo@host1.com 1051 4.2.7 Inline Encoding 1053 Parameter Name: ENCODING 1055 Purpose: To specify an alternate inline encoding for the property 1056 value. 1058 Format Definition: The property parameter is defined by the following 1059 notation: 1061 encodingparam = "ENCODING" "=" 1062 ("8BIT" 1063 ; "8bit" text encoding is defined in [RFC 2045] 1064 / "BASE64" 1065 ; "BASE64" binary encoding format is defined in [RFC 2045] 1066 / iana-token 1067 ; Some other IANA registered iCalendar encoding type 1068 / x-name) 1069 ; A non-standard, experimental encoding type 1071 Description: The property parameter identifies the inline encoding 1072 used in a property value. The default encoding is "8BIT", 1073 corresponding to a property value consisting of text. The "BASE64" 1074 encoding type corresponds to a property value encoded using the 1075 "BASE64" encoding defined in [RFC 2045]. 1077 If the value type parameter is ";VALUE=BINARY", then the inline 1078 encoding parameter MUST be specified with the value 1079 ";ENCODING=BASE64". 1081 Example: 1083 ATTACH;FMTYPE=IMAGE/JPEG;ENCODING=BASE64;VALUE=BINARY:MIICajC 1084 CAdOgAwIBAgICBEUwDQYJKoZIhvcNAQEEBQAwdzELMAkGA1UEBhMCVVMxLDA 1085 qBgNVBAoTI05ldHNjYXBlIENvbW11bmljYXRpb25zIENvcnBvcmF0aW9uMRw 1086 <...remainder of "BASE64" encoded binary data...> 1088 4.2.8 Format Type 1090 Parameter Name: FMTTYPE 1092 Purpose: To specify the content type of a referenced object. 1094 Format Definition: The property parameter is defined by the following 1095 notation: 1097 Dawson/Stenerson 21 Expires February 1999 1098 fmttypeparam = "FMTTYPE" "=" iana-token 1099 ; A IANA registered content type 1100 / x-name 1101 ; A non-standard content type 1103 Description: This parameter can be specified on properties that are 1104 used to reference an object. The parameter specifies the content type 1105 of the referenced object. For example, on the "ATTACH" property, a 1106 FTP type URI value does not, by itself, necessarily convey the type 1107 of content associated with the resource. The parameter value MUST be 1108 the TEXT for either an IANA registered content type or a non-standard 1109 content type. 1111 Example: 1113 ATTACH;FMTTYPE=application/binary:ftp://domain.com/pub/docs/ 1114 agenda.doc 1116 4.2.9 Free/Busy Time Type 1118 Parameter Name: FBTYPE 1120 Purpose: To specify the free or busy time type. 1122 Format Definition: The property parameter is defined by the following 1123 notation: 1125 fbtypeparam = "FBTYPE" "=" ("FREE" / "BUSY" 1126 / "BUSY-UNAVAILABLE" / "BUSY-TENTATIVE" 1127 / x-name 1128 ; Some experimental iCalendar data type. 1129 / iana-token) 1130 ; Some other IANA registered iCalendar data type. 1132 Description: The parameter specifies the free or busy time type. The 1133 value FREE indicates that the time interval is free for scheduling. 1134 The value BUSY indicates that the time interval is busy because one 1135 or more events have been scheduled for that interval. The value BUSY- 1136 UNAVAILABLE indicates that the time interval is busy and that the 1137 interval can not be scheduled. The value BUSY-TENTATIVE indicates 1138 that the time interval is busy because one or more events have been 1139 tentatively scheduled for that interval. If not specified on a 1140 property that allows this parameter, the default is BUSY. 1142 Example: The following is an example of this parameter on a FREEBUSY 1143 property. 1145 FREEBUSY;FBTYPE=BUSY:19980415T133000Z/19980415T170000Z 1147 4.2.10 Language 1149 Parameter Name: LANGUAGE 1151 Dawson/Stenerson 22 Expires February 1999 1152 Purpose: To specify the language for text values in a property or 1153 property parameter. 1155 Format Definition: The property parameter is defined by the following 1156 notation: 1158 languageparam = "LANGUAGE" "=" language 1160 language = 1162 Description: This parameter can be specified on properties with a 1163 text value type. The parameter identifies the language of the text in 1164 the property or property parameter value. The value of the "language" 1165 property parameter is that defined in [RFC 1766]. 1167 For transport in a MIME entity, the Content-Language header field can 1168 be used to set the default language for the entire body part. 1169 Otherwise, no default language is assumed. 1171 Example: 1173 SUMMARY;LANGUAGE=us-EN:Company Holiday Party 1175 LOCATION;LANGUAGE=en:Germany 1176 LOCATION;LANGUAGE=no:Tyskland 1178 The following example makes use of the Quoted-Printable encoding in 1179 order to represent non-ASCII characters. 1181 LOCATION;LANGUAGE=da:K=F8benhavn 1182 LOCATION;LANGUAGE=en:Copenhagen 1184 4.2.11 Group or List Membership 1186 Parameter Name: MEMBER 1188 Purpose: To specify the group or list membership of the calendar user 1189 specified by the property. 1191 Format Definition: The property parameter is defined by the following 1192 notation: 1194 memberparam = "MEMBER" "=" DQUOTE cal-address DQUOTE 1195 *("," DQUOTE cal-address DQUOTE) 1197 Description: This parameter can be specified on properties with a 1198 CAL-ADDRESS value type. The parameter identifies the groups or list 1199 membership for the calendar user specified by the property. The 1200 parameter value either a single calendar address in a quoted-string 1201 or a COMMA character (US-ASCII decimal 44) list of calendar 1202 addresses, each in a quoted-string. The individual calendar address 1203 parameter values MUST each be specified in a quoted-string. 1205 Dawson/Stenerson 23 Expires February 1999 1206 Example: 1208 ATTENDEE;MEMBER="MAILTO:ietf-calsch@imc.org":MAILTO:jsmith@host.com 1210 ATTENDEE;MEMBER="MAILTO:projectA@host.com","MAILTO:projectB@host. 1211 com":MAILTO:janedoe@host.com 1213 4.2.12 Participation Status 1215 Parameter Name: PARTSTAT 1217 Purpose: To specify the participation status for the calendar user 1218 specified by the property. 1220 Format Definition: The property parameter is defined by the following 1221 notation: 1223 partstatparam = "PARTSTAT" "=" 1224 ("NEEDS-ACTION" ; Event needs action 1225 / "ACCEPTED" ; Event accepted 1226 / "DECLINED" ; Event declined 1227 / "TENTATIVE" ; Event tentatively 1228 ; accepted 1229 / "DELEGATED" ; Event delegated 1230 / x-name ; Experimental status 1231 / iana-token) ; Other IANA registered 1232 ; status 1233 ; These are the participation statuses for a "VEVENT". Default is 1234 ; NEEDS-ACTION 1236 partstatparam /= "PARTSTAT" "=" 1237 ("NEEDS-ACTION" ; To-do needs action 1238 / "ACCEPTED" ; To-do accepted 1239 / "DECLINED" ; To-do declined 1240 / "TENTATIVE" ; To-do tentatively 1241 ; accepted 1242 / "DELEGATED" ; To-do delegated 1243 / "COMPLETED" ; To-do completed. 1244 ; COMPLETED property has 1245 ;date/time completed. 1246 / "IN-PROCESS" ; To-do in process of 1247 ; being completed 1248 / x-name ; Experimental status 1249 / iana-token) ; Other IANA registered 1250 ; status 1251 ; These are the participation statuses for a "VTODO". Default is 1252 ; NEEDS-ACTION 1254 partstatparam /= "PARTSTAT" "=" 1255 ("NEEDS-ACTION" ; Journal needs action 1256 / "ACCEPTED" ; Journal accepted 1257 / "DECLINED" ; Journal declined 1258 / x-name ; Experimental status 1260 Dawson/Stenerson 24 Expires February 1999 1261 / iana-token) ; Other IANA registered 1262 ; status 1263 ; These are the participation statuses for a "VJOURNAL". Default is 1264 ; NEEDS-ACTION 1266 Description: This parameter can be specified on properties with a 1267 CAL-ADDRESS value type. The parameter identifies the participation 1268 status for the calendar user specified by the property value. The 1269 parameter values differ depending on whether they are associated with 1270 a group scheduled "VEVENT", "VTODO" or "VJOURNAL". The values MUST 1271 match one of the values allowed for the given calendar component. If 1272 not specified on a property that allows this parameter, the default 1273 value is NEEDS-ACTION. 1275 Example: 1277 ATTENDEE;PARTSTAT=DECLINED:MAILTO:jsmith@host.com 1279 4.2.13 Recurrence Identifier Range 1281 Parameter Name: RANGE 1283 Purpose: To specify the effective range of recurrence instances from 1284 the instance specified by the recurrence identifier specified by the 1285 property. 1287 Format Definition: The property parameter is defined by the following 1288 notation: 1290 rangeparam = "RANGE" "=" ("THISANDPRIOR" 1291 ; To specify all instances prior to the recurrence identifier 1292 / "THISANDFUTURE") 1293 ; To specify the instance specified by the recurrence identifier 1294 ; and all subsequent recurrence instances 1296 Description: The parameter can be specified on a property that 1297 specifies a recurrence identifier. The parameter specifies the 1298 effective range of recurrence instances that is specified by the 1299 property. The effective range is from the recurrence identified 1300 specified by the property. If this parameter is not specified an 1301 allowed property, then the default range is the single instance 1302 specified by the recurrence identifier value of the property. The 1303 parameter value can be "THISANDPRIOR" to indicate a range defined by 1304 the recurrence identified value of the property and all prior 1305 instances. The parameter value can also be "THISANDFUTURE" to 1306 indicate a range defined by the recurrence identifier and all 1307 subsequent instances. 1309 Example: 1311 RECURRENCE-ID;RANGE=THISANDPRIOR:19980401T133000Z 1313 Dawson/Stenerson 25 Expires February 1999 1314 4.2.14 Alarm Trigger Relationship 1316 Parameter Name: RELATED 1318 Purpose: To specify the relationship of the alarm trigger with 1319 respect to the start or end of the calendar component. 1321 Format Definition: The property parameter is defined by the following 1322 notation: 1324 trigrelparam = "RELATED" "=" 1325 ("START" ; Trigger off of start 1326 / "END") ; Trigger off of end 1328 Description: The parameter can be specified on properties that 1329 specify an alarm trigger with a DURATION value type. The parameter 1330 specifies whether the alarm will trigger relative to the start or end 1331 of the calendar component. The parameter value START will set the 1332 alarm to trigger off the start of the calendar component; the 1333 parameter value END will set the alarm to trigger off the end of the 1334 calendar component. If the parameter is not specified on an allowable 1335 property, then the default is START. 1337 Example: 1339 TRIGGER;RELATED=END:PT5M 1341 4.2.15 Relationship Type 1343 Parameter Name: RELTYPE 1345 Purpose: To specify the type of hierarchical relationship associated 1346 with the calendar component specified by the property. 1348 Format Definition: The property parameter is defined by the following 1349 notation: 1351 reltypeparam = "RELTYPE" "=" 1352 ("PARENT" ; Parent relationship. Default. 1353 / "CHILD" ; Child relationship 1354 / "SIBLING ; Sibling relationship 1355 / iana-token ; Some other IANA registered 1356 ; iCalendar relationship type 1357 / x-name) ; A non-standard, experimental 1358 ; relationship type 1360 Description: This parameter can be specified on a property that 1361 references another related calendar. The parameter specifies the 1362 hierarchical relationship type of the calendar component referenced 1363 by the property. The parameter value can be PARENT, to indicate that 1364 the referenced calendar component is a superior of calendar 1365 component; CHILD to indicate that the referenced calendar component 1366 is a subordinate of the calendar component; SIBLING to indicate that 1368 Dawson/Stenerson 26 Expires February 1999 1369 the referenced calendar component is a peer of the calendar 1370 component. If this parameter is not specified on an allowable 1371 property, the default relationship type is PARENT. 1373 Example: 1375 RELATED-TO;RELTYPE=SIBLING:<19960401-080045-4000F192713@host.com> 1377 4.2.16 Participation Role 1379 Parameter Name: ROLE 1381 Purpose: To specify the participation role for the calendar user 1382 specified by the property. 1384 Format Definition: The property parameter is defined by the following 1385 notation: 1387 roleparam = "ROLE" "=" 1388 ("CHAIR" ; Indicates chair of the 1389 ; calendar entity 1390 / "REQ-PARTICIPANT" ; Indicates a participant whose 1391 ; participation is required 1392 / "OPT-PARTICIPANT" ; Indicates a participant whose 1393 ; participation is optional 1394 / "NON-PARTICIPANT" ; Indicates a participant who is 1395 ; copied for information 1396 ; purposes only 1397 / x-name ; Experimental role 1398 / iana-token) ; Other IANA role 1399 ; Default is REQ-PARTICIPANT 1401 Description: This parameter can be specified on properties with a 1402 CAL-ADDRESS value type. The parameter specifies the participation 1403 role for the calendar user specified by the property in the group 1404 schedule calendar component. If not specified on a property that 1405 allows this parameter, the default value is REQ-PARTICIPANT. 1407 Example: 1409 ATTENDEE;ROLE=CHAIR:MAILTO:mrbig@host.com 1411 4.2.17 RSVP Expectation 1413 Parameter Name: RSVP 1415 Purpose: To specify whether there is an expectation of a favor of a 1416 reply from the calendar user specified by the property value. 1418 Format Definition: The property parameter is defined by the following 1419 notation: 1421 Dawson/Stenerson 27 Expires February 1999 1422 rsvpparam = "RSVP" "=" ("TRUE" / "FALSE") 1423 ; Default is FALSE 1425 Description: This parameter can be specified on properties with a 1426 CAL-ADDRESS value type. The parameter identifies the expectation of a 1427 reply from the calendar user specified by the property value. This 1428 parameter is used by the "Organizer" to request a participation 1429 status reply from an "Attendee" of a group scheduled event or to-do. 1430 If not specified on a property that allows this parameter, the 1431 default value is FALSE. 1433 Example: 1435 ATTENDEE;RSVP=TRUE:MAILTO:jsmith@host.com 1437 4.2.18 Sent By 1439 Parameter Name: SENT-BY 1441 Purpose: To specify the calendar user that is acting on behalf of the 1442 calendar user specified by the property. 1444 Format Definition: The property parameter is defined by the following 1445 notation: 1447 sentbyparam = "SENT-BY" "=" DQUOTE cal-address DQUOTE 1449 Description: This parameter can be specified on properties with a 1450 CAL-ADDRESS value type. The parameter specifies the calendar user 1451 that is acting on behalf of the calendar user specified by the 1452 property. The parameter value MUST be a MAILTO URI as defined in [RFC 1453 1738]. The individual calendar address parameter values MUST each be 1454 specified in a quoted-string. 1456 Example: 1458 ORGANIZER;SENT-BY:"MAILTO:sray@host.com":MAILTO:jsmith@host.com 1460 4.2.19 Time Zone Identifier 1462 Parameter Name: TZID 1464 Purpose: To specify the identifier for the time zone definition for a 1465 time component in the property value. 1467 Format Definition: This property parameter is defined by the 1468 following notation: 1470 tzidparam = "TZID" "=" [tzidprefix] paramtext CRLF 1472 tzidprefix = "/" 1474 Dawson/Stenerson 28 Expires February 1999 1475 Description: The parameter MUST be specified on the "DTSTART", 1476 "DTEND", "DUE", "EXDATE" and "RDATE" properties when either a DATE- 1477 TIME or TIME value type is specified and when the value is not either 1478 a UTC or a "floating" time. Refer to the DATE-TIME or TIME value type 1479 definition for a description of UTC and "floating time" formats. This 1480 property parameter specifies a text value which uniquely identifies 1481 the "VTIMEZONE" calendar component to be used when evaluating the 1482 time portion of the property. The value of the TZID property 1483 parameter will be equal to the value of the TZID property for the 1484 matching time zone definition. An individual "VTIMEZONE" calendar 1485 component MUST be specified for each unique "TZID" parameter value 1486 specified in the iCalendar object. 1488 The parameter MUST be specified on properties with a DATE-TIME value 1489 if the DATE-TIME is not either a UTC or a "floating" time. 1491 The presence of the SOLIDUS character (US-ASCII decimal 47) as a 1492 prefix, indicates that this TZID represents a unique ID in a globally 1493 defined time zone registry (when such registry is defined). 1495 Note: This document does not define a naming convention for time 1496 zone identifiers. Implementers may want to use the naming 1497 conventions defined in existing time zone specifications such as 1498 the public-domain Olson database [TZ]. The specification of 1499 globally unique time zone identifiers is not addressed by this 1500 document and is left for future study. 1502 The following are examples of this property parameter: 1504 DTSTART;TZID=US-Eastern:19980119T020000 1506 DTEND;TZID=US-Eastern:19980119T030000 1508 The TZID property parameter MUST NOT be applied to DATE-TIME or TIME 1509 properties whose time values are specified in UTC. 1511 The use of local time in a DATE-TIME or TIME value without the TZID 1512 property parameter is to be interpreted as a local time value, 1513 regardless of the existence of "VTIMEZONE" calendar components in the 1514 iCalendar object. 1516 For more information see the sections on the data types DATE-TIME and 1517 TIME. 1519 4.2.20 Value Data Types 1521 Parameter Name: VALUE 1523 Purpose: To explicitly specify the data type format for a property 1524 value. 1526 Format Definition: The "VALUE" property parameter is defined by the 1527 following notation: 1529 Dawson/Stenerson 29 Expires February 1999 1530 valuetypeparam = "VALUE" "=" valuetype 1532 valuetype = ("BINARY" 1533 / "BOOLEAN" 1534 / "CAL-ADDRESS" 1535 / "DATE" 1536 / "DATE-TIME" 1537 / "DURATION" 1538 / "FLOAT" 1539 / "INTEGER" 1540 / "PERIOD" 1541 / "RECUR" 1542 / "TEXT" 1543 / "TIME" 1544 / "URI" 1545 / "UTC-OFFSET" 1546 / x-name 1547 ; Some experimental iCalendar data type. 1548 / iana-token) 1549 ; Some other IANA registered iCalendar data type. 1551 Description: The parameter specifies the data type and format of the 1552 property value. The property values MUST be of a single value type. 1553 For example, a "RDATE" property cannot have a combination of DATE- 1554 TIME and TIME value types. 1556 If the property's value is the default value type, then this 1557 parameter need not be specified. However, if the property's default 1558 value type is overridden by some other allowable value type, then 1559 this parameter MUST be specified. 1561 4.3 Property Value Data Types 1563 The properties in an iCalendar object are strongly typed. The 1564 definition of each property restricts the value to be one of the 1565 value data types, or simply value types, defined in this section. The 1566 value type for a property will either be specified implicitly as the 1567 default value type or will be explicitly specified with the "VALUE" 1568 parameter. If the value type of a property is one of the alternate 1569 valid types, then it MUST be explicitly specified with the "VALUE" 1570 parameter. 1572 4.3.1 Binary 1574 Value Name: BINARY 1576 Purpose: This value type is used to identify properties that contain 1577 a character encoding of inline binary data. For example, an inline 1578 attachment of an object code might be included in an iCalendar 1579 object. 1581 Formal Definition: The value type is defined by the following 1582 notation: 1584 Dawson/Stenerson 30 Expires February 1999 1585 binary = *(4b-char) [b-end] 1586 ; A "BASE64" encoded character string, as defined by [RFC 2045]. 1588 b-end = (2b-char "==") / (3b-char "=") 1590 b-char = ALPHA / DIGIT / "+" / "/" 1592 Description: Property values with this value type MUST also include 1593 the inline encoding parameter sequence of ";ENCODING=BASE64". That 1594 is, all inline binary data MUST first be character encoded using the 1595 "BASE64" encoding method defined in [RFC 2045]. No additional content 1596 value encoding (i.e., BACKSLASH character encoding) is defined for 1597 this value type. 1599 Example: The following is an abridged example of a "BASE64" encoded 1600 binary value data. 1602 ATTACH;VALUE=BINARY;ENCODING=BASE64:MIICajCCAdOgAwIBAgICBEUwDQY 1603 JKoZIhvcNAQEEBQAwdzELMAkGA1UEBhMCVVMxLDAqBgNVBAoTI05ldHNjYXBlI 1604 ENvbW11bmljYXRpb25zIENvcnBvcmF0aW9uMRwwGgYDVQQLExNJbmZv 1605 <...remainder of "BASE64" encoded binary data...> 1607 4.3.2 Boolean 1609 Value Name: BOOLEAN 1611 Purpose: This value type is used to identify properties that contain 1612 either a "TRUE" or "FALSE" Boolean value. 1614 Formal Definition: The value type is defined by the following 1615 notation: 1617 boolean = "TRUE" / "FALSE" 1619 Description: These values are case insensitive text. No additional 1620 content value encoding (i.e., BACKSLASH character encoding) is 1621 defined for this value type. 1623 Example: The following is an example of a hypothetical property that 1624 has a BOOLEAN value type: 1626 GIBBERISH:TRUE 1628 4.3.3 Calendar User Address 1630 Value Name: CAL-ADDRESS 1632 Purpose: This value type is used to identify properties that contain 1633 a calendar user address. 1635 Formal Definition: The value type is as defined by the following 1636 notation: 1638 Dawson/Stenerson 31 Expires February 1999 1639 cal-address = uri 1641 Description: The value is a URI as defined by [RFC 1738] or any other 1642 IANA registered form for a URI. When used to address an Internet 1643 email transport address for a calendar user, the value MUST be a 1644 MAILTO URI, as defined by [RFC 1738]. No additional content value 1645 encoding (i.e., BACKSLASH character encoding) is defined for this 1646 value type. 1648 Example: 1650 ATTENDEE:MAILTO:jane_doe@host.com 1652 4.3.4 Date 1654 Value Name: DATE 1656 Purpose: This value type is used to identify values that contain a 1657 calendar date. 1659 Formal Definition: The value type is defined by the following 1660 notation: 1662 date = date-value 1664 date-value = date-fullyear date-month date-mday 1665 date-fullyear = 4DIGIT 1666 date-month = 2DIGIT ;01-12 1667 date-mday = 2DIGIT ;01-28, 01-29, 01-30, 01-31 1668 ;based on month/year 1670 Description: If the property permits, multiple "date" values are 1671 specified as a COMMA character (US-ASCII decimal 44) separated list 1672 of values. The format for the value type is expressed as the [ISO 1673 8601] complete representation, basic format for a calendar date. The 1674 textual format specifies a four-digit year, two-digit month, and two- 1675 digit day of the month. There are no separator characters between the 1676 year, month and day component text. 1678 No additional content value encoding (i.e., BACKSLASH character 1679 encoding) is defined for this value type. 1681 Example: The following represents July 14, 1997: 1683 19970714 1685 4.3.5 Date-Time 1687 Value Name: DATE-TIME 1689 Purpose: This value type is used to identify values that specify a 1690 precise calendar date and time of day. 1692 Dawson/Stenerson 32 Expires February 1999 1693 Formal Definition: The value type is defined by the following 1694 notation: 1696 date-time = date "T" time ;As specified in the date and time 1697 ;value definitions 1699 Description: If the property permits, multiple "date-time" values are 1700 specified as a COMMA character (US-ASCII decimal 44) separated list 1701 of values. No additional content value encoding (i.e., BACKSLASH 1702 character encoding) is defined for this value type. 1704 The "DATE-TIME" data type is used to identify values that contain a 1705 precise calendar date and time of day. The format is based on the 1706 [ISO 8601] complete representation, basic format for a calendar date 1707 and time of day. The text format is a concatenation of the "date", 1708 followed by the LATIN CAPITAL LETTER T character (US-ASCII decimal 1709 84) time designator, followed by the "time" format. 1711 The "DATE-TIME" data type expresses time values in three forms: 1713 The form of date and time with UTC offset MUST NOT be used. For 1714 example, the following is not valid for a date-time value: 1716 DTSTART:19980119T230000-0800 ;Invalid time format 1718 FORM #1: DATE WITH LOCAL TIME 1720 The date with local time form is simply a date-time value that does 1721 not contain the UTC designator nor does it reference a time zone. For 1722 example, the following represents Janurary 18, 1998, at 11 PM: 1724 DTSTART:19980118T230000 1726 Date-time values of this type are said to be "floating" and are not 1727 bound to any time zone in particular. They are used to represent the 1728 same hour, minute, and second value regardless of which time zone is 1729 currently being observed. For example, an event can be defined that 1730 indicates that an individual will be busy from 11:00 AM to 1:00 PM 1731 every day, no matter which time zone the person is in. In these 1732 cases, a local time can be specified. The recipient of an iCalendar 1733 object with a property value consisting of a local time, without any 1734 relative time zone information, SHOULD interpret the value as being 1735 fixed to whatever time zone the ATTENDEE is in at any given moment. 1736 This means that two ATTENDEEs, in different time zones, receiving the 1737 same event definition as a floating time, may be participating in the 1738 event at different actual times. Floating time SHOULD only be used 1739 where that is the reasonable behavior. 1741 In most cases, a fixed time is desired. To properly communicate a 1742 fixed time in a property value, either UTC time or local time with 1743 time zone reference MUST be specified. 1745 Dawson/Stenerson 33 Expires February 1999 1746 The use of local time in a DATE-TIME value without the TZID property 1747 parameter is to be interpreted as floating time, regardless of the 1748 existence of "VTIMEZONE" calendar components in the iCalendar object. 1750 FORM #2: DATE WITH UTC TIME 1752 The date with UTC time, or absolute time, is identified by a LATIN 1753 CAPITAL LETTER Z suffix character (US-ASCII decimal 90), the UTC 1754 designator, appended to the time value. For example, the following 1755 represents January 19, 1998, at 0700 UTC: 1757 DTSTART:19980119T070000Z 1759 The TZID property parameter MUST NOT be applied to DATE-TIME 1760 properties whose time values are specified in UTC. 1762 FORM #3: DATE WITH LOCAL TIME AND TIME ZONE REFERENCE 1764 The date and local time with reference to time zone information is 1765 identified by the use the TZID property parameter to reference the 1766 appropriate time zone definition. TZID is discussed in detail in the 1767 section on Time Zone. For example, the following represents 2 AM in 1768 New York on Janurary 19, 1998: 1770 DTSTART;TZID=US-Eastern:19980119T020000 1772 Example: The following represents July 14, 1997, at 1:30 PM in New 1773 York City in each of the three time formats, using the "DTSTART" 1774 property. 1776 DTSTART:19970714T133000 ;Local time 1777 DTSTART:19970714T173000Z ;UTC time 1778 DTSTART;TZID=US-Eastern:19970714T133000 ;Local time and time 1779 ; zone reference 1781 A time value MUST ONLY specify 60 seconds when specifying the 1782 periodic "leap second" in the time value. For example: 1784 COMPLETED:19970630T235960Z 1786 4.3.6 Duration 1788 Value Name: DURATION 1790 Purpose: This value type is used to identify properties that contain 1791 a duration of time. 1793 Formal Definition: The value type is defined by the following 1794 notation: 1796 dur-value = (["+"] / "-") "P" (dur-date / dur-time / dur-week) 1798 Dawson/Stenerson 34 Expires February 1999 1799 dur-date = dur-day [dur-time] 1800 dur-time = "T" (dur-hour / dur-minute / dur-second) 1801 dur-week = 1*DIGIT "W" 1802 dur-hour = 1*DIGIT "H" [dur-minute] 1803 dur-minute = 1*DIGIT "M" [dur-second] 1804 dur-second = 1*DIGIT "S" 1805 dur-day = 1*DIGIT "D" 1807 Description: If the property permits, multiple "duration" values are 1808 specified by a COMMA character (US-ASCII decimal 44) separated list 1809 of values. The format is expressed as the [ISO 8601] basic format for 1810 the duration of time. The format can represent durations in terms of 1811 weeks, days, hours, minutes, and seconds. 1813 No additional content value encoding (i.e., BACKSLASH character 1814 encoding) are defined for this value type. 1816 Example: A duration of 15 days, 5 hours and 20 seconds would be: 1818 P15DT5H0M20S 1820 A duration of 7 weeks would be: 1822 P7W 1824 4.3.7 Float 1826 Value Name: FLOAT 1828 Purpose: This value type is used to identify properties that contain 1829 a real number value. 1831 Formal Definition: The value type is defined by the following 1832 notation: 1834 float = (["+"] / "-") 1*DIGIT ["." 1*DIGIT] 1836 Description: If the property permits, multiple "float" values are 1837 specified by a COMMA character (US-ASCII decimal 44) separated list 1838 of values. 1840 No additional content value encoding (i.e., BACKSLASH character 1841 encoding) is defined for this value type. 1843 Example: 1845 1000000.0000001 1846 1.333 1847 -3.14 1849 4.3.8 Integer 1851 Value Name:INTEGER 1853 Dawson/Stenerson 35 Expires February 1999 1854 Purpose: This value type is used to identify properties that contain 1855 a signed integer value. 1857 Formal Definition: The value type is defined by the following 1858 notation: 1860 integer = (["+"] / "-") 1*DIGIT 1862 Description: If the property permits, multiple "integer" values are 1863 specified by a COMMA character (US-ASCII decimal 44) separated list 1864 of values. The valid range for "integer" is -2147483648 to 1865 2147483647. If the sign is not specified, then the value is assumed 1866 to be positive. 1868 No additional content value encoding (i.e., BACKSLASH character 1869 encoding) is defined for this value type. 1871 Example: 1873 1234567890 1874 -1234567890 1875 +1234567890 1876 432109876 1878 4.3.9 Period of Time 1880 Value Name: PERIOD 1882 Purpose: This value type is used to identify values that contain a 1883 precise period of time. 1885 Formal Definition: The data type is defined by the following 1886 notation: 1888 period = period-explicit / period-start 1890 period-explicit = date-time "/" date-time 1891 ; [ISO 8601] complete representation basic format for a period of 1892 ; time consisting of a start and end. The start MUST be before the 1893 ; end. 1895 period-start = date-time "/" dur-value 1896 ; [ISO 8601] complete representation basic format for a period of 1897 ; time consisting of a start and positive duration of time. 1899 Description: If the property permits, multiple "period" values are 1900 specified by a COMMA character (US-ASCII decimal 44) separated list 1901 of values. There are two forms of a period of time. First, a period 1902 of time is identified by its start and its end. This format is 1903 expressed as the [ISO 8601] complete representation, basic format for 1904 "DATE-TIME" start of the period, followed by a SOLIDUS character (US- 1905 ASCII decimal 47), followed by the "DATE-TIME" of the end of the 1906 period. The start of the period MUST be before the end of the period. 1908 Dawson/Stenerson 36 Expires February 1999 1909 Second, a period of time can also be defined by a start and a 1910 positive duration of time. The format is expressed as the [ISO 8601] 1911 complete representation, basic format for the "DATE-TIME" start of 1912 the period, followed by a SOLIDUS character (US-ASCII decimal 47), 1913 followed by the [ISO 8601] basic format for "DURATION" of the period. 1915 Example: The period starting at 18:00:00 UTC, on January 1, 1997 and 1916 ending at 07:00:00 UTC on January 2, 1997 would be: 1918 19970101T180000Z/19970102T070000Z 1920 The period start at 18:00:00 on January 1, 1997 and lasting 5 hours 1921 and 30 minutes would be: 1923 19970101T180000Z/PT5H30M 1925 No additional content value encoding (i.e., BACKSLASH character 1926 encoding) is defined for this value type. 1928 4.3.10 Recurrence Rule 1930 Value Name: RECUR 1932 Purpose: This value type is used to identify properties that contain 1933 a recurrence rule specification. 1935 Formal Definition: The value type is defined by the following 1936 notation: 1938 recur = "FREQ"=freq *( 1940 ; either UNTIL or COUNT may appear in a 'recur', 1941 ; but UNTIL and COUNT MUST NOT occur in the same 'recur' 1943 ( ";" "UNTIL" "=" enddate ) / 1944 ( ";" "COUNT" "=" 1*DIGIT ) / 1946 ; the rest of these keywords are optional, 1947 ; but MUST NOT occur more than once 1949 ( ";" "INTERVAL" "=" 1*DIGIT ) / 1950 ( ";" "BYSECOND" "=" byseclist ) / 1951 ( ";" "BYMINUTE" "=" byminlist ) / 1952 ( ";" "BYHOUR" "=" byhrlist ) / 1953 ( ";" "BYDAY" "=" bywdaylist ) / 1954 ( ";" "BYMONTHDAY" "=" bymodaylist ) / 1955 ( ";" "BYYEARDAY" "=" byyrdaylist ) / 1956 ( ";" "BYWEEKNO" "=" bywknolist ) / 1957 ( ";" "BYMONTH" "=" bymolist ) / 1958 ( ";" "BYSETPOS" "=" bysplist ) / 1959 ( ";" "WKST" "=" weekday ) / 1960 ( ";" x-name "=" text ) 1961 ) 1963 Dawson/Stenerson 37 Expires February 1999 1964 freq = "SECONDLY" / "MINUTELY" / "HOURLY" / "DAILY" 1965 / "WEEKLY" / "MONTHLY" / "YEARLY" 1967 enddate = date 1968 enddate =/ date-time ;An UTC value 1970 byseclist = seconds / ( seconds *("," seconds) ) 1972 seconds = 1DIGIT / 2DIGIT ;0 to 59 1974 byminlist = minutes / ( minutes *("," minutes) ) 1976 minutes = 1DIGIT / 2DIGIT ;0 to 59 1978 byhrlist = hour / ( hour *("," hour) ) 1980 hour = 1DIGIT / 2DIGIT ;0 to 23 1982 bywdaylist = weekdaynum / ( weekdaynum *("," weekdaynum) ) 1984 weekdaynum = [([plus] ordwk / minus ordwk)] weekday 1986 plus = "+" 1988 minus = "-" 1990 ordwk = 1DIGIT / 2DIGIT ;1 to 53 1992 weekday = "SU" / "MO" / "TU" / "WE" / "TH" / "FR" / "SA" 1993 ;Corresponding to SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, 1994 ;FRIDAY, SATURDAY and SUNDAY days of the week. 1996 bymodaylist = monthdaynum / ( monthdaynum *("," monthdaynum) ) 1998 monthdaynum = ([plus] ordmoday) / (minus ordmoday) 2000 ordmoday = 1DIGIT / 2DIGIT ;1 to 31 2002 byyrdaylist = yeardaynum / ( yeardaynum *("," yeardaynum) ) 2004 yeardaynum = ([plus] ordyrday) / (minus ordyrday) 2006 ordyrday = 1DIGIT / 2DIGIT / 3DIGIT ;1 to 366 2008 bywknolist = weeknum / ( weeknum *("," weeknum) ) 2010 weeknum = ([plus] ordwk) / (minus ordwk) 2012 bymolist = monthnum / ( monthnum *("," monthnum) ) 2014 monthnum = 1DIGIT / 2DIGIT ;1 to 12 2016 bysplist = setposday / ( setposday *("," setposday) ) 2018 Dawson/Stenerson 38 Expires February 1999 2019 setposday = yeardaynum 2021 Description: If the property permits, multiple "recur" values are 2022 specified by a COMMA character (US-ASCII decimal 44) separated list 2023 of values. The value type is a structured value consisting of a list 2024 of one or more recurrence grammar parts. Each rule part is defined by 2025 a NAME=VALUE pair. The rule parts are separated from each other by 2026 the SEMICOLON character (US-ASCII decimal 59). The rule parts are not 2027 ordered in any particular sequence. Individual rule parts MUST only 2028 be specified once. 2030 The FREQ rule part identifies the type of recurrence rule. This rule 2031 part MUST be specified in the recurrence rule. Valid values include 2032 SECONDLY, to specify repeating events based on an interval of a 2033 second or more; MINUTELY, to specify repeating events based on an 2034 interval of a minute or more; HOURLY, to specify repeating events 2035 based on an interval of an hour or more; DAILY, to specify repeating 2036 events based on an interval of a day or more; WEEKLY, to specify 2037 repeating events based on an interval of a week or more; MONTHLY, to 2038 specify repeating events based on an interval of a month or more; and 2039 YEARLY, to specify repeating events based on an interval of a year or 2040 more. 2042 The INTERVAL rule part contains a positive integer representing how 2043 often the recurrence rule repeats. The default value is "1", meaning 2044 every second for a SECONDLY rule, or every minute for a MINUTELY 2045 rule, every hour for an HOURLY rule, every day for a DAILY rule, 2046 every week for a WEEKLY rule, every month for a MONTHLY rule and 2047 every year for a YEARLY rule. 2049 The UNTIL rule part defines a date-time value which bounds the 2050 recurrence rule in an inclusive manner. If the value specified by 2051 UNTIL is synchronized with the specified recurrence, this date or 2052 date-time becomes the last instance of the recurrence. If specified 2053 as a date-time value, then it MUST be specified in an UTC time 2054 format. If not present, and the COUNT rule part is also not present, 2055 the RRULE is considered to repeat forever. 2057 The COUNT rule part defines the number of occurrences at which to 2058 range-bound the recurrence. The "DTSTART" property value, if 2059 specified, counts as the first occurrence. 2061 The BYSECOND rule part specifies a COMMA character (US-ASCII decimal 2062 44) separated list of seconds within a minute. Valid values are 0 to 2063 59. The BYMINUTE rule part specifies a COMMA character (US-ASCII 2064 decimal 44) separated list of minutes within an hour. Valid values 2065 are 0 to 59. The BYHOUR rule part specifies a COMMA character (US- 2066 ASCII decimal 44) separated list of hours of the day. Valid values 2067 are 0 to 23. 2069 The BYDAY rule part specifies a COMMA character (US-ASCII decimal 44) 2070 separated list of days of the week; MO indicates Monday; TU indicates 2071 Tuesday; WE indicates Wednesday; TH indicates Thursday; FR indicates 2072 Friday; SA indicates Saturday; SU indicates Sunday. 2074 Dawson/Stenerson 39 Expires February 1999 2075 Each BYDAY value can also be preceded by a positive (+n) or negative 2076 (-n) integer. If present, this indicates the nth occurrence of the 2077 specific day within the MONTHLY or YEARLY RRULE. For example, within 2078 a MONTHLY rule, +1MO (or simply 1MO) represents the first Monday 2079 within the month, whereas -1MO represents the last Monday of the 2080 month. If an integer modifier is not present, it means all days of 2081 this type within the specified frequency. For example, within a 2082 MONTHLY rule, MO represents all Mondays within the month. 2084 The BYMONTHDAY rule part specifies a COMMA character (ASCII decimal 2085 44) separated list of days of the month. Valid values are 1 to 31 or 2086 -31 to -1. For example, -10 represents the tenth to the last day of 2087 the month. 2089 The BYYEARDAY rule part specifies a COMMA character (US-ASCII 2090 decimal 44) separated list of days of the year. Valid values are 1 to 2091 366 or -366 to -1. For example, -1 represents the last day of the 2092 year (December 31st) and -306 represents the 306th to the last day of 2093 the year (March 1st). 2095 The BYWEEKNO rule part specifies a COMMA character (US-ASCII decimal 2096 44) separated list of ordinals specifying weeks of the year. Valid 2097 values are 1 to 53 or -53 to -1. This corresponds to weeks according 2098 to week numbering as defined in [ISO 8601]. A week is defined as a 2099 seven day period, starting on the day of the week defined to be the 2100 week start (see WKST). Week number one of the calendar year is the 2101 first week which contains at least four (4) days in that calendar 2102 year. This rule part is only valid for YEARLY rules. For example, 3 2103 represents the third week of the year. 2105 Note: Assuming a Monday week start, week 53 can only occur when 2106 Thursday is January 1 or if it is a leap year and Wednesday is 2107 January 1. 2109 The BYMONTH rule part specifies a COMMA character (US-ASCII decimal 2110 44) separated list of months of the year. Valid values are 1 to 12. 2112 The WKST rule part specifies the day on which the workweek starts. 2113 Valid values are MO, TU, WE, TH, FR, SA and SU. This is significant 2114 when a WEEKLY RRULE has an interval greater than 1, and a BYDAY rule 2115 part is specified. This is also significant when in a YEARLY RRULE 2116 when a BYWEEKNO rule part is specified. The default value is MO. 2118 The BYSETPOS rule part specifies a COMMA character (US-ASCII decimal 2119 44) separated list of values which corresponds to the nth occurrence 2120 within the set of events specified by the rule. Valid values are 1 to 2121 366 or -366 to -1. It MUST only be used in conjunction with another 2122 BYxxx rule part. For example "the last work day of the month" could 2123 be represented as: 2125 RRULE:FREQ=MONTHLY;BYDAY=MO,TU,WE,TH,FR;BYSETPOS=-1 2127 Dawson/Stenerson 40 Expires February 1999 2128 Each BYSETPOS value can include a positive (+n) or negative (-n) 2129 integer. If present, this indicates the nth occurrence of the 2130 specific occurrence within the set of events specified by the rule. 2132 If BYxxx rule part values are found which are beyond the available 2133 scope (ie, BYMONTHDAY=30 in February), they are simply ignored. 2135 Information, not contained in the rule, necessary to determine the 2136 various recurrence instance start time and dates are derived from the 2137 Start Time (DTSTART) entry attribute. For example, 2138 "FREQ=YEARLY;BYMONTH=1" doesn�t specify a specific day within the 2139 month or a time. This information would be the same as what is 2140 specified for DTSTART. 2142 BYxxx rule parts modify the recurrence in some manner. BYxxx rule 2143 parts for a period of time which is the same or greater than the 2144 frequency generally reduce or limit the number of occurrences of the 2145 recurrence generated. For example, "FREQ=DAILY;BYMONTH=1" reduces the 2146 number of recurrence instances from all days (if BYMONTH tag is not 2147 present) to all days in January. BYxxx rule parts for a period of 2148 time less than the frequency generally increase or expand the number 2149 of occurrences of the recurrence. For example, 2150 "FREQ=YEARLY;BYMONTH=1,2" increases the number of days within the 2151 yearly recurrence set from 1 (if BYMONTH tag is not present) to 2. 2153 If multiple BYxxx rule parts are specified, then after evaluating the 2154 specified FREQ and INTERVAL rule parts, the BYxxx rule parts are 2155 applied to the current set of evaluated occurrences in the following 2156 order: BYMONTH, BYWEEKNO, BYYEARDAY, BYMONTHDAY, BYDAY, BYHOUR, 2157 BYMINUTE, BYSECOND and BYSETPOS; then COUNT and UNTIL are evaluated. 2159 Here is an example of evaluating multiple BYxxx rule parts. 2161 DTSTART;TZID=US-Eastern:19970105T083000 2162 RRULE:FREQ=YEARLY;INTERVAL=2;BYMONTH=1;BYDAY=SU;BYHOUR=8,9; 2163 BYMINUTE=30 2165 First, the "INTERVAL=2" would be applied to "FREQ=YEARLY" to arrive 2166 at "every other year". Then, "BYMONTH=1" would be applied to arrive 2167 at "every January, every other year". Then, "BYDAY=SU" would be 2168 applied to arrive at "every Sunday in January, every other year". 2169 Then, "BYHOUR=8,9" would be applied to arrive at "every Sunday in 2170 January at 8 AM and 9 AM, every other year". Then, "BYMINUTE=30" 2171 would be applied to arrive at "every Sunday in January at 8:30 AM and 2172 9:30 AM, every other year". Then, lacking information from RRULE, the 2173 second is derived from DTSTART, to end up in "every Sunday in January 2174 at 8:30:00 AM and 9:30:00 AM, every other year". Similarly, if the 2175 BYMINUTE, BYHOUR, BYDAY, BYMONTHDAY or BYMONTH rule part were 2176 missing, the appropriate minute, hour, day or month would have been 2177 retrieved from the "DTSTART" property. 2179 No additional content value encoding (i.e., BACKSLASH character 2180 encoding) is defined for this value type. 2182 Dawson/Stenerson 41 Expires February 1999 2183 Example: The following is a rule which specifies 10 meetings which 2184 occur every other day: 2186 FREQ=DAILY;COUNT=10;INTERVAL=2 2188 There are other examples specified in the "RRULE" specification. 2190 4.3.11 Text 2192 Value Name: TEXT 2194 Purpose This value type is used to identify values that contain human 2195 readable text. 2197 Formal Definition: The character set supported by this revision of 2198 iCalendar is UTF-8 and the valid subsets thereof. The value type is 2199 defined by the following notation. 2201 text = *(TSAFE-CHAR / ":" / DQUOTE / ESCAPED-CHAR) 2202 ; Folded according to description above 2204 ESCAPED-CHAR = "\\" / "\;" / "\," / "\N" / "\n") 2205 ; \\ encodes \, \N or \n encodes newline 2206 ; \; encodes ;, \, encodes , 2208 TSAFE-CHAR = %x20-21 / %x23-2B / %x2D-39 / %x3C-5B 2209 %x5D-7E / NON-US-ASCII 2210 ; Any character except CTLs not needed by the current 2211 ; character set, DQUOTE, ";", ":", "\", "," 2213 Note: Certain other character sets may require modification of the 2214 above definitions, but this is beyond the scope of this document. 2216 Description: If the property permits, multiple "text" values are 2217 specified by a COMMA character (US-ASCII decimal 44) separated list 2218 of values. 2220 The language in which the text is represented can be controlled by 2221 the "LANGUAGE" property parameter. 2223 An intentional formatted text line break MUST only be included in a 2224 "TEXT" property value by representing the line break with the 2225 character sequence of BACKSLASH (US-ASCII decimal 92), followed by a 2226 LATIN SMALL LETTER N (US-ASCII decimal 110) or a LATIN CAPITAL LETTER 2227 N (US-ASCII decimal 78), that is "\n" or "\N". 2229 The "TEXT" property values may also contain special characters that 2230 are used to signify delimiters, such as a COMMA character for lists 2231 of values or a SEMICOLON character for structured values. In order to 2232 support the inclusion of these special characters in "TEXT" property 2233 values, they MUST be escaped with a BACKSLASH character. A BACKSLASH 2234 character (US-ASCII decimal 92) in a "TEXT" property value MUST be 2235 escaped with another BACKSLASH character. A COMMA character in a 2237 Dawson/Stenerson 42 Expires February 1999 2238 "TEXT" property value MUST be escaped with a BACKSLASH character (US- 2239 ASCII decimal 92). A SEMICOLON character in a "TEXT" property value 2240 MUST be escaped with a BACKSLASH character (US-ASCII decimal 92). 2241 However, a COLON character in a "TEXT" property value SHALL NOT be 2242 escaped with a BACKSLASH character.Example: A multiple line value of: 2244 Project XYZ Final Review 2245 Conference Room - 3B 2246 Come Prepared. 2248 would be represented as: 2250 Project XYZ Final Review\nConference Room - 3B\nCome Prepared. 2252 4.3.12 Time 2254 Value Name: TIME 2256 Purpose: This value type is used to identify values that contain a 2257 time of day. 2259 Formal Definition: The data type is defined by the following 2260 notation: 2262 time = time-hour time-minute time-second [time-utc] 2264 time-hour = 2DIGIT ;00-23 2265 time-minute = 2DIGIT ;00-59 2266 time-second = 2DIGIT ;00-60 2267 ;The "60" value is used to account for "leap" seconds. 2269 time-utc = "Z" 2271 Description: If the property permits, multiple "time" values are 2272 specified by a COMMA character (US-ASCII decimal 44) separated list 2273 of values. No additional content value encoding (i.e., BACKSLASH 2274 character encoding) is defined for this value type. 2276 The "TIME" data type is used to identify values that contain a time 2277 of day. The format is based on the [ISO 8601] complete 2278 representation, basic format for a time of day. The text format 2279 consists of a two-digit 24-hour of the day (i.e., values 0-23), two- 2280 digit minute in the hour (i.e., values 0-59), and two-digit seconds 2281 in the minute (i.e., values 0-60). The seconds value of 60 MUST only 2282 to be used to account for "leap" seconds. Fractions of a second are 2283 not supported by this format. 2285 In parallel to the "DATE-TIME" definition above, the "TIME" data type 2286 expresses time values in three forms: 2288 The form of time with UTC offset MUST NOT be used. For example, the 2289 following is NOT VALID for a time value: 2291 Dawson/Stenerson 43 Expires February 1999 2292 230000-0800 ;Invalid time format 2294 FORM #1 LOCAL TIME 2296 The local time form is simply a time value that does not contain the 2297 UTC designator nor does it reference a time zone. For example, 11:00 2298 PM: 2300 230000 2302 Time values of this type are said to be "floating" and are not bound 2303 to any time zone in particular. They are used to represent the same 2304 hour, minute, and second value regardless of which time zone is 2305 currently being observed. For example, an event can be defined that 2306 indicates that an individual will be busy from 11:00 AM to 1:00 PM 2307 every day, no matter which time zone the person is in. In these 2308 cases, a local time can be specified. The recipient of an iCalendar 2309 object with a property value consisting of a local time, without any 2310 relative time zone information, SHOULD interpret the value as being 2311 fixed to whatever time zone the ATTENDEE is in at any given moment. 2312 This means that two ATTENDEEs may participate in the same event at 2313 different UTC times; floating time SHOULD only be used where that is 2314 reasonable behavior. 2316 In most cases, a fixed time is desired. To properly communicate a 2317 fixed time in a property value, either UTC time or local time with 2318 time zone reference MUST be specified. 2320 The use of local time in a TIME value without the TZID property 2321 parameter is to be interpreted as a local time value, regardless of 2322 the existence of "VTIMEZONE" calendar components in the iCalendar 2323 object. 2325 FORM #2: UTC TIME 2327 UTC time, or absolute time, is identified by a LATIN CAPITAL LETTER Z 2328 suffix character (US-ASCII decimal 90), the UTC designator, appended 2329 to the time value. For example, the following represents 07:00 AM 2330 UTC: 2332 070000Z 2334 The TZID property parameter MUST NOT be applied to TIME properties 2335 whose time values are specified in UTC. 2337 FORM #3: LOCAL TIME AND TIME ZONE REFERENCE 2339 The local time with reference to time zone information form is 2340 identified by the use the TZID property parameter to reference the 2341 appropriate time zone definition. TZID is discussed in detail in the 2342 section on Time Zone. 2344 Dawson/Stenerson 44 Expires February 1999 2345 Example: The following represents 8:30 AM in New York in Winter, five 2346 hours behind UTC, in each of the three formats using the "X- 2347 TIMEOFDAY" non-standard property: 2349 X-TIMEOFDAY:083000 2351 X-TIMEOFDAY:133000Z 2353 X-TIMEOFDAY;TZID=US-Eastern:083000 2355 4.3.13 URI 2357 Value Name: URI 2359 Purpose: This value type is used to identify values that contain a 2360 uniform resource identifier (URI) type of reference to the property 2361 value. 2363 Formal Definition: The data type is defined by the following 2364 notation: 2366 uri = 2368 Description: This data type might be used to reference binary 2369 information, for values that are large, or otherwise undesirable to 2370 include directly in the iCalendar object. 2372 The URI value formats in RFC 1738, RFC 2111 and any other IETF 2373 registered value format can be specified. 2375 Any IANA registered URI format can be used. These include, but are 2376 not limited to, those defined in RFC 1738 and RFC 2111. 2378 When a property parameter value is a URI value type, the URI MUST be 2379 specified as a quoted-string value. 2381 No additional content value encoding (i.e., BACKSLASH character 2382 encoding) is defined for this value type. 2384 Example: The following is a URI for a network file: 2386 http://host1.com/my-report.txt 2388 4.3.14 UTC Offset 2390 Value Name: UTC-OFFSET 2392 Purpose: This value type is used to identify properties that contain 2393 an offset from UTC to local time. 2395 Formal Definition: The data type is defined by the following 2396 notation: 2398 Dawson/Stenerson 45 Expires February 1999 2399 utc-offset = time-numzone ;As defined above in time data type 2401 time-numzone = ("+" / "-") time-hour time-minute [time- 2402 second] 2404 Description: The PLUS SIGN character MUST be specified for positive 2405 UTC offsets (i.e., ahead of UTC). The value of "-0000" and "-000000" 2406 are not allowed. The time-second, if present, may not be 60; if 2407 absent, it defaults to zero. 2409 No additional content value encoding (i.e., BACKSLASH character 2410 encoding) is defined for this value type. 2412 Example: The following UTC offsets are given for standard time for 2413 New York (five hours behind UTC) and Geneva (one hour ahead of UTC): 2415 -0500 2417 +0100 2419 4.4 iCalendar Object 2421 The Calendaring and Scheduling Core Object is a collection of 2422 calendaring and scheduling information. Typically, this information 2423 will consist of a single iCalendar object. However, multiple 2424 iCalendar objects can be sequentially grouped together. The first 2425 line and last line of the iCalendar object MUST contain a pair of 2426 iCalendar object delimiter strings. The syntax for an iCalendar 2427 object is as follows: 2429 icalobject = 1*("BEGIN" ":" "VCALENDAR" CRLF 2430 icalbody 2431 "END" ":" "VCALENDAR" CRLF) 2433 The following is a simple example of an iCalendar object: 2435 BEGIN:VCALENDAR 2436 VERSION:2.0 2437 PRODID:-//hacksw/handcal//NONSGML v1.0//EN 2438 BEGIN:VEVENT 2439 DTSTART:19970714T170000Z 2440 DTEND:19970715T035959Z 2441 SUMMARY:Bastille Day Party 2442 END:VEVENT 2443 END:VCALENDAR 2445 4.5 Property 2447 A property is the definition of an individual attribute describing a 2448 calendar or a calendar component. A property takes the form defined 2449 by the "contentline" notation defined in section 4.1.1. 2451 The following is an example of a property: 2453 Dawson/Stenerson 46 Expires February 1999 2454 DTSTART:19960415T133000Z 2456 This memo imposes no ordering of properties within an iCalendar 2457 object. 2459 Property names, parameter names and enumerated parameter values are 2460 case insensitive. For example, the property name "DUE" is the same as 2461 "due" and "Due", DTSTART;TZID=US-Eastern:19980714T120000 is the same 2462 as DtStart;TzID=US-Eastern:19980714T120000. 2464 4.6 Calendar Components 2466 The body of the iCalendar object consists of a sequence of calendar 2467 properties and one or more calendar components. The calendar 2468 properties are attributes that apply to the calendar as a whole. The 2469 calendar components are collections of properties that express a 2470 particular calendar semantic. For example, the calendar component can 2471 specify an event, a to-do, a journal entry, time zone information, or 2472 free/busy time information, or an alarm. 2474 The body of the iCalendar object is defined by the following 2475 notation: 2477 icalbody = calprops component 2479 calprops = 2*( 2481 ; 'prodid' and 'version' are both REQUIRED, 2482 ; but MUST NOT occur more than once 2484 prodid /version / 2486 ; 'calscale' and 'method' are optional, 2487 ; but MUST NOT occur more than once 2489 calscale / 2490 method / 2492 x-prop 2494 ) 2496 component = 1*(eventc / todoc / journalc / freebusyc / 2497 / timezonec / iana-comp / x-comp) 2499 iana-comp = "BEGIN" ":" iana-token CRLF 2501 1*contentline 2503 "END" ":" iana-token CRLF 2505 x-comp = "BEGIN" ":" x-name CRLF 2507 Dawson/Stenerson 47 Expires February 1999 2508 1*contentline 2510 "END" ":" x-name CRLF 2512 An iCalendar object MUST include the "PRODID" and "VERSION" calendar 2513 properties. In addition, it MUST include at least one calendar 2514 component. Special forms of iCalendar objects are possible to publish 2515 just busy time (i.e., only a "VFREEBUSY" calendar component) or time 2516 zone (i.e., only a "VTIMEZONE" calendar component) information. In 2517 addition, a complex iCalendar object is possible that is used to 2518 capture a complete snapshot of the contents of a calendar (e.g., 2519 composite of many different calendar components). More commonly, an 2520 iCalendar object will consist of just a single "VEVENT", "VTODO" or 2521 "VJOURNAL" calendar component. 2523 4.6.1 Event Component 2525 Component Name: "VEVENT" 2527 Purpose: Provide a grouping of component properties that describe an 2528 event. 2530 Format Definition: A "VEVENT" calendar component is defined by the 2531 following notation: 2533 eventc = "BEGIN" ":" "VEVENT" CRLF 2534 eventprop *alarmc 2535 "END" ":" "VEVENT" CRLF 2537 eventprop = *( 2539 ; the following are optional, 2540 ; but MUST NOT occur more than once 2542 class / created / description / dtstart / geo / 2543 last-mod / location / organizer / priority / 2544 dtstamp / seq / status / summary / transp / 2545 uid / url / recurid / 2547 ; either 'dtend' or 'duration' may appear in 2548 ; a 'eventprop', but 'dtend' and 'duration' 2549 ; MUST NOT occur in the same 'eventprop' 2551 dtend / duration / 2553 ; the following are optional, 2554 ; and MAY occur more than once 2556 attach / attendee / categories / comment / 2557 contact / exdate / exrule / rstatus / related / 2558 resources / rdate / rrule / x-prop 2560 ) 2562 Dawson/Stenerson 48 Expires February 1999 2563 Description: A "VEVENT" calendar component is a grouping of component 2564 properties, and possibly including "VALARM" calendar components, that 2565 represents a scheduled amount of time on a calendar. For example, it 2566 can be an activity; such as a one-hour long, department meeting from 2567 8:00 AM to 9:00 AM, tomorrow. Generally, an event will take up time 2568 on an individual calendar. Hence, the event will appear as an opaque 2569 interval in a search for busy time. Alternately, the event can have 2570 its Time Transparency set to "TRANSPARENT" in order to prevent 2571 blocking of the event in searches for busy time. 2573 The "VEVENT" is also the calendar component used to specify an 2574 anniversary or daily reminder within a calendar. These events have a 2575 DATE value type for the "DTSTART" property instead of the default 2576 data type of DATE-TIME. If such a "VEVENT" has a "DTEND" property, it 2577 MUST be specified as a DATE value also. The anniversary type of 2578 "VEVENT" can span more than one date (i.e, "DTEND" property value is 2579 set to a calendar date after the "DTSTART" property value). 2581 The "DTSTART" property for a "VEVENT" specifies the inclusive start 2582 of the event. For recurring events, it also specifies the very first 2583 instance in the recurrence set. The "DTEND" property for a "VEVENT" 2584 calendar component specifies the non-inclusive end of the event. For 2585 cases where a "VEVENT" calendar component specifies a "DTSTART" 2586 property with a DATE data type but no "DTEND" property, the events 2587 non-inclusive end is the end of the calendar date specified by the 2588 "DTSTART" property. For cases where a "VEVENT" calendar component 2589 specifies a "DTSTART" property with a DATE-TIME data type but no 2590 "DTEND" property, the event ends on the same calendar date and time 2591 of day specified by the "DTSTART" property. 2593 The "VEVENT" calendar component cannot be nested within another 2594 calendar component. However, "VEVENT" calendar components can be 2595 related to each other or to a "VTODO" or to a "VJOURNAL" calendar 2596 component with the "RELATED-TO" property. 2598 Example: The following is an example of the "VEVENT" calendar 2599 component used to represent a meeting that will also be opaque to 2600 searches for busy time: 2602 BEGIN:VEVENT 2603 UID:19970901T130000Z-123401@host.com 2604 DTSTAMP:19970901T1300Z 2605 DTSTART:19970903T163000Z 2606 DTEND:19970903T190000Z 2607 SUMMARY:Annual Employee Review 2608 CLASS:PRIVATE 2609 CATEGORIES:BUSINESS,HUMAN RESOURCES 2610 END:VEVENT 2612 The following is an example of the "VEVENT" calendar component used 2613 to represent a reminder that will not be opaque, but rather 2614 transparent, to searches for busy time: 2616 Dawson/Stenerson 49 Expires February 1999 2617 BEGIN:VEVENT 2618 UID:19970901T130000Z-123402@host.com 2619 DTSTAMP:19970901T1300Z 2620 DTSTART:19970401T163000Z 2621 DTEND:19970402T010000Z 2622 SUMMARY:Laurel is in sensitivity awareness class. 2623 CLASS:PUBLIC 2624 CATEGORIES:BUSINESS,HUMAN RESOURCES 2625 TRANSP:TRANSPARENT 2626 END:VEVENT 2628 The following is an example of the "VEVENT" calendar component used 2629 to represent an anniversary that will occur annually. Since it takes 2630 up no time, it will not appear as opaque in a search for busy time; 2631 no matter what the value of the "TRANSP" property indicates: 2633 BEGIN:VEVENT 2634 UID:19970901T130000Z-123403@host.com 2635 DTSTAMP:19970901T1300Z 2636 DTSTART:19971102 2637 SUMMARY:Our Blissful Anniversary 2638 CLASS:CONFIDENTIAL 2639 CATEGORIES:ANNIVERSARY,PERSONAL,SPECIAL OCCASION 2640 RRULE:FREQ=YEARLY 2641 END:VEVENT 2643 4.6.2 To-do Component 2645 Component Name: VTODO 2647 Purpose: Provide a grouping of calendar properties that describe a 2648 to-do. 2650 Formal Definition: A "VTODO" calendar component is defined by the 2651 following notation: 2653 todoc = "BEGIN" ":" "VTODO" CRLF 2654 todoprop *alarmc 2655 "END" ":" "VTODO" CRLF 2657 todoprop = *( 2659 ; the following are optional, 2660 ; but MUST NOT occur more than once 2662 class / completed / created / description / dtstamp / 2663 dtstart / geo / last-mod / location / organizer / 2664 percent / priority / recurid / seq / status / 2665 summary / uid / url / 2667 ; either 'due' or 'duration' may appear in 2668 ; a 'todoprop', but 'due' and 'duration' 2669 ; MUST NOT occur in the same 'todoprop' 2671 Dawson/Stenerson 50 Expires February 1999 2672 due / duration / 2674 ; the following are optional, 2675 ; and MAY occur more than once 2677 attach / attendee / categories / comment / contact / 2678 exdate / exrule / rstatus / related / resources / 2679 rdate / rrule / x-prop 2681 ) 2683 Description: A "VTODO" calendar component is a grouping of component 2684 properties and possibly "VALARM" calendar components that represent 2685 an action-item or assignment. For example, it can be used to 2686 represent an item of work assigned to an individual; such as "turn in 2687 travel expense today". 2689 The "VTODO" calendar component cannot be nested within another 2690 calendar component. However, "VTODO" calendar components can be 2691 related to each other or to a "VTODO" or to a "VJOURNAL" calendar 2692 component with the "RELATED-TO" property. 2694 A "VTODO" calendar component without the "DTSTART" and "DUE" (or 2695 "DURATION") properties specifies a to-do that will be associated with 2696 each successive calendar date, until it is completed. 2698 Example: The following is an example of a "VTODO" calendar component: 2700 BEGIN:VTODO 2701 UID:19970901T130000Z-123404@host.com 2702 DTSTAMP:19970901T1300Z 2703 DTSTART:19970415T133000Z 2704 DUE:19970416T045959Z 2705 SUMMARY:1996 Income Tax Preparation 2706 CLASS:CONFIDENTIAL 2707 CATEGORIES:FAMILY,FINANCE 2708 PRIORITY:1 2709 STATUS:NEEDS-ACTION 2710 END:VEVENT 2712 4.6.3 Journal Component 2714 Component Name: VJOURNAL 2716 Purpose: Provide a grouping of component properties that describe a 2717 journal entry. 2719 Formal Definition: A "VJOURNAL" calendar component is defined by the 2720 following notation: 2722 journalc = "BEGIN" ":" "VJOURNAL" CRLF 2723 jourprop 2724 "END" ":" "VJOURNAL" CRLF 2726 Dawson/Stenerson 51 Expires February 1999 2727 jourprop = *( 2729 ; the following are optional, 2730 ; but MUST NOT occur more than once 2732 class / created / description / dtstart / dtstamp / 2733 last-mod / organizer / recurid / seq / status / 2734 summary / uid / url / 2736 ; the following are optional, 2737 ; and MAY occur more than once 2739 attach / attendee / categories / comment / 2740 contact / exdate / exrule / related / rdate / 2741 rrule / rstatus / x-prop 2743 ) 2745 Description: A "VJOURNAL" calendar component is a grouping of 2746 component properties that represent one or more descriptive text 2747 notes associated with a particular calendar date. The "DTSTART" 2748 property is used to specify the calendar date that the journal entry 2749 is associated with. Generally, it will have a DATE value data type, 2750 but it can also be used to specify a DATE-TIME value data type. 2751 Examples of a journal entry include a daily record of a legislative 2752 body or a journal entry of individual telephone contacts for the day 2753 or an ordered list of accomplishments for the day. The "VJOURNAL" 2754 calendar component can also be used to associate a document with a 2755 calendar date. 2757 The "VJOURNAL" calendar component does not take up time on a 2758 calendar. Hence, it does not play a role in free or busy time 2759 searches - - it is as though it has a time transparency value of 2760 TRANSPARENT. It is transparent to any such searches. 2762 The "VJOURNAL" calendar component cannot be nested within another 2763 calendar component. However, "VJOURNAL" calendar components can be 2764 related to each other or to a "VEVENT" or to a "VTODO" calendar 2765 component, with the "RELATED-TO" property. 2767 Example: The following is an example of the "VJOURNAL" calendar 2768 component: 2770 BEGIN:VJOURNAL 2771 UID:19970901T130000Z-123405@host.com 2772 DTSTAMP:19970901T1300Z 2773 DTSTART;VALUE=DATE:19970317 2774 SUMMARY:Staff meeting minutes 2775 DESCRIPTION:1. Staff meeting: Participants include Joe\, Lisa 2776 and Bob. Aurora project plans were reviewed. There is currently 2777 no budget reserves for this project. Lisa will escalate to 2778 management. Next meeting on Tuesday.\n 2779 2. Telephone Conference: ABC Corp. sales representative called 2780 to discuss new printer. Promised to get us a demo by Friday.\n 2782 Dawson/Stenerson 52 Expires February 1999 2783 3. Henry Miller (Handsoff Insurance): Car was totaled by tree. 2784 Is looking into a loaner car. 654-2323 (tel). 2785 END:VJOURNAL 2787 4.6.4 Free/Busy Component 2789 Component Name: VFREEBUSY 2791 Purpose: Provide a grouping of component properties that describe 2792 either a request for free/busy time, describe a response to a request 2793 for free/busy time or describe a published set of busy time. 2795 Formal Definition: A "VFREEBUSY" calendar component is defined by the 2796 following notation: 2798 freebusyc = "BEGIN" ":" "VFREEBUSY" CRLF 2799 fbprop 2800 "END" ":" "VFREEBUSY" CRLF 2802 fbprop = *( 2804 ; the following are optional, 2805 ; but MUST NOT occur more than once 2807 contact / dtstart / dtend / duration / dtstamp / 2808 organizer / uid / url / 2810 ; the following are optional, 2811 ; and MAY occur more than once 2813 attendee / comment / freebusy / rstatus / x-prop 2815 ) 2817 Description: A "VFREEBUSY" calendar component is a grouping of 2818 component properties that represents either a request for, a reply to 2819 a request for free or busy time information or a published set of 2820 busy time information. 2822 When used to request free/busy time information, the "ATTENDEE" 2823 property specifies the calendar users whose free/busy time is being 2824 requested; the "ORGANIZER" property specifies the calendar user who 2825 is requesting the free/busy time; the "DTSTART" and "DTEND" 2826 properties specify the window of time for which the free/busy time is 2827 being requested; the "UID" and "DTSTAMP" properties are specified to 2828 assist in proper sequencing of multiple free/busy time requests. 2830 When used to reply to a request for free/busy time, the "ATTENDEE" 2831 property specifies the calendar user responding to the free/busy time 2832 request; the "ORGANIZER" property specifies the calendar user that 2833 originally requested the free/busy time; the "FREEBUSY" property 2834 specifies the free/busy time information (if it exists); and the 2836 Dawson/Stenerson 53 Expires February 1999 2837 "UID" and "DTSTAMP" properties are specified to assist in proper 2838 sequencing of multiple free/busy time replies. 2840 When used to publish busy time, the "ORGANIZER" property specifies 2841 the calendar user associated with the published busy time; the 2842 "DTSTART" and "DTEND" properties specify an inclusive time window 2843 that surrounds the busy time information; the "FREEBUSY" property 2844 specifies the published busy time information; and the "DTSTAMP" 2845 property specifies the date/time that iCalendar object was created. 2847 The "VFREEBUSY" calendar component cannot be nested within another 2848 calendar component. Multiple "VFREEBUSY" calendar components can be 2849 specified within an iCalendar object. This permits the grouping of 2850 Free/Busy information into logical collections, such as monthly 2851 groups of busy time information. 2853 The "VFREEBUSY" calendar component is intended for use in iCalendar 2854 object methods involving requests for free time, requests for busy 2855 time, requests for both free and busy, and the associated replies. 2857 Free/Busy information is represented with the "FREEBUSY" property. 2858 This property provides a terse representation of time periods. One or 2859 more "FREEBUSY" properties can be specified in the "VFREEBUSY" 2860 calendar component. 2862 When present in a "VFREEBUSY" calendar component, the "DTSTART" and 2863 "DTEND" properties SHOULD be specified prior to any "FREEBUSY" 2864 properties. In a free time request, these properties can be used in 2865 combination with the "DURATION" property to represent a request for a 2866 duration of free time within a specified window of time. 2868 The recurrence properties ("RRULE", "EXRULE", "RDATE", "EXDATE") are 2869 not permitted within a "VFREEBUSY" calendar component. Any recurring 2870 events are resolved into their individual busy time periods using the 2871 "FREEBUSY" property. 2873 Example: The following is an example of a "VFREEBUSY" calendar 2874 component used to request free or busy time information: 2876 BEGIN:VFREEBUSY 2877 ORGANIZER:MAILTO:jane_doe@host1.com 2878 ATTENDEE:MAILTO:john_public@host2.com 2879 DTSTART:19971015T050000Z 2880 DTEND:19971016T050000Z 2881 DTSTAMP:19970901T083000Z 2882 END:VFREEBUSY 2884 The following is an example of a "VFREEBUSY" calendar component used 2885 to reply to the request with busy time information: 2887 BEGIN:VFREEBUSY 2888 ORGANIZER:MAILTO:jane_doe@host1.com 2889 ATTENDEE:MAILTO:john_public@host2.com 2890 DTSTAMP:19970901T100000Z 2892 Dawson/Stenerson 54 Expires February 1999 2893 FREEBUSY;VALUE=PERIOD:19971015T050000Z/PT8H30M, 2894 19971015T160000Z/PT5H30M,19971015T223000Z/PT6H30M 2895 URL:http://host2.com/pub/busy/jpublic-01.ifb 2896 COMMENT:This iCalendar file contains busy time information for 2897 the next three months. 2898 END:VFREEBUSY 2900 The following is an example of a "VFREEBUSY" calendar component used 2901 to publish busy time information. 2903 BEGIN:VFREEBUSY 2904 ORGANIZER:jsmith@host.com 2905 DTSTART:19980313T141711Z 2906 DTEND:19980410T141711Z 2907 FREEBUSY:19980314T233000Z/19980315T003000Z 2908 FREEBUSY:19980316T153000Z/19980316T163000Z 2909 FREEBUSY:19980318T030000Z/19980318T040000Z 2910 URL:http://www.host.com/calendar/busytime/jsmith.ifb 2911 END:VFREEBUSY 2913 4.6.5 Time Zone Component 2915 Component Name: VTIMEZONE 2917 Purpose: Provide a grouping of component properties that defines a 2918 time zone. 2920 Formal Definition: A "VTIMEZONE" calendar component is defined by the 2921 following notation: 2923 timezonec = "BEGIN" ":" "VTIMEZONE" CRLF 2925 2*( 2927 ; 'tzid' is required, but MUST NOT occur more 2928 ; than once 2930 tzid / 2932 ; 'last-mod' and 'tzurl' are optional, 2933 but MUST NOT occur more than once 2935 last-mod / tzurl / 2937 ; one of 'standardc' or 'daylightc' MUST occur 2938 ..; and each MAY occur more than once. 2940 standardc / daylightc / 2942 ; the following is optional, 2943 ; and MAY occur more than once 2945 x-prop 2947 Dawson/Stenerson 55 Expires February 1999 2948 ) 2950 "END" ":" "VTIMEZONE" CRLF 2952 standardc = "BEGIN" ":" "STANDARD" CRLF 2954 tzprop 2956 "END" ":" "STANDARD" CRLF 2958 daylightc = "BEGIN" ":" "DAYLIGHT" CRLF 2960 tzprop 2962 "END" ":" "DAYLIGHT" CRLF 2964 tzprop = 3*( 2966 ; the following are each REQUIRED, 2967 ; but MUST NOT occur more than once 2969 dtstart / tzoffsetto / tzoffsetfrom / 2971 ; the following are optional, 2972 ; and MAY occur more than once 2974 comment / rdate / rrule / tzname / x-prop 2976 ) 2978 Description: A time zone is unambiguously defined by the set of time 2979 measurement rules determined by the governing body for a given 2980 geographic area. These rules describe at a minimum the base offset 2981 from UTC for the time zone, often referred to as the Standard Time 2982 offset. Many locations adjust their Standard Time forward or backward 2983 by one hour, in order to accommodate seasonal changes in number of 2984 daylight hours, often referred to as Daylight Saving Time. Some 2985 locations adjust their time by a fraction of an hour. Standard Time 2986 is also known as Winter Time. Daylight Saving Time is also known as 2987 Advanced Time, Summer Time, or Legal Time in certain countries. The 2988 following table shows the changes in time zone rules in effect for 2989 New York City starting from 1967. Each line represents a description 2990 or rule for a particular observance. 2992 Effective Observance Rule 2994 Date (Date/Time) Offset Abbreviation 2996 1967-* last Sun in Oct, 02:00 -0500 EST 2998 1967-1973 last Sun in Apr, 02:00 -0400 EDT 3000 1974-1974 Jan 6, 02:00 -0400 EDT 3002 Dawson/Stenerson 56 Expires February 1999 3003 1975-1975 Feb 23, 02:00 -0400 EDT 3005 1976-1986 last Sun in Apr, 02:00 -0400 EDT 3007 1987-* first Sun in Apr, 02:00 -0400 EDT 3009 Note: The specification of a global time zone registry is not 3010 addressed by this document and is left for future study. 3011 However, implementers may find the Olson time zone database [TZ] 3012 a useful reference. It is an informal, public-domain collection 3013 of time zone information, which is currently being maintained by 3014 volunteer Internet participants, and is used in several 3015 operating systems. This database contains current and historical 3016 time zone information for a wide variety of locations around the 3017 globe; it provides a time zone identifier for every unique time 3018 zone rule set in actual use since 1970, with historical data 3019 going back to the introduction of standard time. 3021 Interoperability between two calendaring and scheduling applications, 3022 especially for recurring events, to-dos or journal entries, is 3023 dependent on the ability to capture and convey date and time 3024 information in an unambiguous format. The specification of current 3025 time zone information is integral to this behavior. 3027 If present, the "VTIMEZONE" calendar component defines the set of 3028 Standard Time and Daylight Saving Time observances (or rules) for a 3029 particular time zone for a given interval of time. The "VTIMEZONE" 3030 calendar component cannot be nested within other calendar components. 3031 Multiple "VTIMEZONE" calendar components can exist in an iCalendar 3032 object. In this situation, each "VTIMEZONE" MUST represent a unique 3033 time zone definition. This is necessary for some classes of events, 3034 such as airline flights, that start in one time zone and end in 3035 another. 3037 The "VTIMEZONE" calendar component MUST be present if the iCalendar 3038 object contains an RRULE that generates dates on both sides of a time 3039 zone shift (e.g. both in Standard Time and Daylight Saving Time) 3040 unless the iCalendar object intends to convey a floating time (See 3041 the section "4.1.10.11 Time" for proper interpretation of floating 3042 time). It can be present if the iCalendar object does not contain 3043 such a RRULE. In addition, if a RRULE is present, there MUST be valid 3044 time zone information for all recurrence instances. 3046 The "VTIMEZONE" calendar component MUST include the "TZID" property 3047 and at least one definition of a standard or daylight component. The 3048 standard or daylight component MUST include the "DTSTART", 3049 "TZOFFSETFROM" and "TZOFFSETTO" properties. 3051 An individual "VTIMEZONE" calendar component MUST be specified for 3052 each unique "TZID" parameter value specified in the iCalendar object. 3054 Each "VTIMEZONE" calendar component consists of a collection of one 3055 or more sub-components that describe the rule for a particular 3056 observance (either a Standard Time or a Daylight Saving Time 3058 Dawson/Stenerson 57 Expires February 1999 3059 observance). The "STANDARD" sub-component consists of a collection of 3060 properties that describe Standard Time. The "DAYLIGHT" sub-component 3061 consists of a collection of properties that describe Daylight Saving 3062 Time. In general this collection of properties consists of: 3064 - the first onset date-time for the observance 3066 - the last onset date-time for the observance, if a last onset 3067 is known. 3069 - the offset to be applied for the observance 3071 - a rule that describes the day and time when the observance 3072 takes effect 3074 - an optional name for the observance 3076 For a given time zone, there may be multiple unique definitions of 3077 the observances over a period of time. Each observance is described 3078 using either a "STANDARD" or "DAYLIGHT" sub-component. The collection 3079 of these sub-components is used to describe the time zone for a given 3080 period of time. The offset to apply at any given time is found by 3081 locating the observance that has the last onset date and time before 3082 the time in question, and using the offset value from that 3083 observance. 3085 The top-level properties in a "VTIMEZONE" calendar component are: 3087 The mandatory "TZID" property is a text value that uniquely 3088 identifies the VTIMZONE calendar component within the scope of an 3089 iCalendar object. 3091 The optional "LAST-MODIFIED" property is a UTC value that specifies 3092 the date and time that this time zone definition was last updated. 3094 The optional "TZURL" property is url value that points to a published 3095 VTIMEZONE definition. TZURL SHOULD refer to a resource that is 3096 accessible by anyone who might need to interpret the object. This 3097 SHOULD NOT normally be a file: URL or other URL that is not widely- 3098 accessible. 3100 The collection of properties that are used to define the STANDARD and 3101 DAYLIGHT sub-components include: 3103 The mandatory "DTSTART" property gives the effective onset date and 3104 local time for the time zone sub-component definition. "DTSTART" in 3105 this usage MUST be specified as a local DATE-TIME value. 3107 The mandatory "TZOFFSETFROM" property gives the UTC offset which is 3108 in use when the onset of this time zone observance begins. 3109 "TZOFFSETFROM" is combined with "DTSTART" to define the effective 3110 onset for the time zone sub-component definition. For example, the 3111 following represents the time at which the observance of Standard 3112 Time took effect in Fall 1967 for New York City: 3114 DTSTART:19671029T020000 3116 Dawson/Stenerson 58 Expires February 1999 3117 TZOFFSETFROM:-0400 3119 The mandatory "TZOFFSETTO " property gives the UTC offset for the 3120 time zone sub-component (Standard Time or Daylight Saving Time) when 3121 this observance is in use. 3123 The optional "TZNAME" property is the customary name for the time 3124 zone. It may be specified multiple times, to allow for specifying 3125 multiple language variants of the time zone names. This could be used 3126 for displaying dates. 3128 If specified, the onset for the observance defined by the time zone 3129 sub-component is defined by either the "RRULE" or "RDATE" property. 3130 If neither is specified, only one sub-component can be specified in 3131 the "VTIMEZONE" calendar component and it is assumed that the single 3132 observance specified is always in effect. 3134 The "RRULE" property defines the recurrence rule for the onset of the 3135 observance defined by this time zone sub-component. Some specific 3136 requirements for the usage of RRULE for this purpose include: 3138 - If observance is known to have an effective end date, the 3139 "UNTIL" recurrence rule parameter MUST be used to specify the 3140 last valid onset of this observance (i.e., the UNTIL date-time 3141 will be equal to the last instance generated by the recurrence 3142 pattern). It MUST be specified in UTC time. 3144 - The "DTSTART" and the "TZOFFSETTO" properties MUST be used 3145 when generating the onset date-time values (instances) from the 3146 RRULE. 3148 Alternatively, the "RDATE" property can be used to define the onset 3149 of the observance by giving the individual onset date and times. 3150 "RDATE" in this usage MUST be specified as a local DATE-TIME value in 3151 UTC time. 3153 The optional "COMMENT" property is also allowed for descriptive 3154 explanatory text. 3156 Example: The following are examples of the "VTIMEZONE" calendar 3157 component: 3159 This is an example showing time zone information for the Eastern 3160 United States using "RDATE" property. Note that this is only suitable 3161 for a recurring event that starts on or later than April 6, 1997 at 3162 03:00:00 EDT (i.e., the earliest effective transition date and time) 3163 and ends no later than April 7, 1998 02:00:00 EST (i.e., latest valid 3164 date and time for EST in this scenario). For example, this can be 3165 used for a recurring event that occurs every Friday, 8am-9:00 AM, 3166 starting June 1, 1997, ending December 31, 1997. 3168 BEGIN:VTIMEZONE 3169 TZID:US-Eastern 3170 LAST-MODIFIED:19870101T000000Z 3172 Dawson/Stenerson 59 Expires February 1999 3173 BEGIN:STANDARD 3174 DTSTART:19971026T020000 3175 RDATE:19971026T020000 3176 TZOFFSETFROM:-0400 3177 TZOFFSETTO:-0500 3178 TZNAME:EST 3179 END:STANDARD 3180 BEGIN:DAYLIGHT 3181 DTSTART:19971026T020000 3182 RDATE:19970406T020000 3183 TZOFFSETFROM:-0500 3184 TZOFFSETTO:-0400 3185 TZNAME:EDT 3186 END:DAYLIGHT 3187 END:VTIMEZONE 3189 This is a simple example showing the current time zone rules for the 3190 Eastern United States using a RRULE recurrence pattern. Note that 3191 there is no effective end date to either of the Standard Time or 3192 Daylight Time rules. This information would be valid for a recurring 3193 event starting today and continuing indefinitely. 3195 BEGIN:VTIMEZONE 3196 TZID:US-Eastern 3197 LAST-MODIFIED:19870101T000000Z 3198 TZURL:http://zones.stds_r_us.net/tz/US-Eastern 3199 BEGIN:STANDARD 3200 DTSTART:19671029T020000 3201 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10 3202 TZOFFSETFROM:-0400 3203 TZOFFSETTO:-0500 3204 TZNAME:EST 3205 END:STANDARD 3206 BEGIN:DAYLIGHT 3207 DTSTART:19870405T020000 3208 RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4 3209 TZOFFSETFROM:-0500 3210 TZOFFSETTO:-0400 3211 TZNAME:EDT 3212 END:DAYLIGHT 3213 END:VTIMEZONE 3215 This is an example showing a fictitious set of rules for the Eastern 3216 United States, where the Daylight Time rule has an effective end date 3217 (i.e., after that date, Daylight Time is no longer observed). 3219 BEGIN:VTIMEZONE 3220 TZID:US--Fictitious-Eastern 3221 LAST-MODIFIED:19870101T000000Z 3222 BEGIN:STANDARD 3223 DTSTART:19671029T020000 3224 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10 3225 TZOFFSETFROM:-0400 3226 TZOFFSETTO:-0500 3228 Dawson/Stenerson 60 Expires February 1999 3229 TZNAME:EST 3230 END:STANDARD 3231 BEGIN:DAYLIGHT 3232 DTSTART:19870405T020000 3233 RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4;UNTIL=19980404T070000Z 3234 TZOFFSETFROM:-0500 3235 TZOFFSETTO:-0400 3236 TZNAME:EDT 3237 END:DAYLIGHT 3238 END:VTIMEZONE 3240 This is an example showing a fictitious set of rules for the Eastern 3241 United States, where the first Daylight Time rule has an effective 3242 end date. There is a second Daylight Time rule that picks up where 3243 the other left off. 3245 BEGIN:VTIMEZONE 3246 TZID:US--Fictitious-Eastern 3247 LAST-MODIFIED:19870101T000000Z 3248 BEGIN:STANDARD 3249 DTSTART:19671029T020000 3250 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10 3251 TZOFFSETFROM:-0400 3252 TZOFFSETTO:-0500 3253 TZNAME:EST 3254 END:STANDARD 3255 BEGIN:DAYLIGHT 3256 DTSTART:19870405T020000 3257 RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4;UNTIL=19980404T070000Z 3258 TZOFFSETFROM:-0500 3259 TZOFFSETTO:-0400 3260 TZNAME:EDT 3261 END:DAYLIGHT 3262 BEGIN:DAYLIGHT 3263 DTSTART:19990424T020000 3264 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=4 3265 TZOFFSETFROM:-0500 3266 TZOFFSETTO:-0400 3267 TZNAME:EDT 3268 END:DAYLIGHT 3269 END:VTIMEZONE 3271 4.6.6 Alarm Component 3273 Component Name: VALARM 3275 Purpose: Provide a grouping of component properties that define an 3276 alarm. 3278 Formal Definition: A "VALARM" calendar component is defined by the 3279 following notation: 3281 Dawson/Stenerson 61 Expires February 1999 3282 alarmc = "BEGIN" ":" "VALARM" CRLF 3283 (audioprop / dispprop / emailprop / procprop) 3284 "END" ":" "VALARM" CRLF 3286 audioprop = 2*( 3288 ; 'action' and 'trigger' are both REQUIRED, 3289 ; but MUST NOT occur more than once 3291 action / trigger / 3293 ; 'duration' and 'repeat' are both optional, 3294 ; and MUST NOT occur more than once each, 3295 ; but if one occurs, so MUST the other 3297 duration / repeat / 3299 ; the following is optional, 3300 ; but MUST NOT occur more than once 3302 attach / 3304 ; the following is optional, 3305 ; and MAY occur more than once 3307 x-prop 3309 ) 3311 dispprop = 3*( 3313 ; the following are all REQUIRED, 3314 ; but MUST NOT occur more than once 3316 action / description / trigger / 3318 ; 'duration' and 'repeat' are both optional, 3319 ; and MUST NOT occur more than once each, 3320 ; but if one occurs, so MUST the other 3322 duration / repeat / 3324 ; the following is optional, 3325 ; and MAY occur more than once 3327 *x-prop 3329 ) 3331 emailprop = 4*( 3333 Dawson/Stenerson 62 Expires February 1999 3334 ; the following are all REQUIRED, 3335 ; but MUST NOT occur more than once 3337 action / description / trigger / summary 3339 ; the following is REQUIRED, 3340 ; and MAY occur more than once 3342 attendee / 3344 ; 'duration' and 'repeat' are both optional, 3345 ; and MUST NOT occur more than once each, 3346 ; but if one occurs, so MUST the other 3348 duration / repeat / 3350 ; the following are optional, 3351 ; and MAY occur more than once 3353 attach / x-prop 3355 ) 3357 procprop = 3*( 3359 ; the following are all REQUIRED, 3360 ; but MUST NOT occur more than once 3362 action / attach / trigger / 3364 ; 'duration' and 'repeat' are both optional, 3365 ; and MUST NOT occur more than once each, 3366 ; but if one occurs, so MUST the other 3368 duration / repeat / 3370 ; 'description' is optional, 3371 ; and MUST NOT occur more than once 3373 description / 3375 ; the following is optional, 3376 ; and MAY occur more than once 3378 x-prop 3380 ) 3382 Description: A "VALARM" calendar component is a grouping of component 3383 properties that is a reminder or alarm for an event or a to-do. For 3384 example, it may be used to define a reminder for a pending event or 3385 an overdue to-do. 3387 Dawson/Stenerson 63 Expires February 1999 3388 The "VALARM" calendar component MUST include the "ACTION" and 3389 "TRIGGER" properties. The "ACTION" property further constrains the 3390 "VALARM" calendar component in the following ways: 3392 When the action is "AUDIO", the alarm can also include one and only 3393 one "ATTACH" property, which MUST point to a sound resource, which is 3394 rendered when the alarm is triggered. 3396 When the action is "DISPLAY", the alarm MUST also include a 3397 "DESCRIPTION" property, which contains the text to be displayed when 3398 the alarm is triggered. 3400 When the action is "EMAIL", the alarm MUST include a "DESCRIPTION" 3401 property, which contains the text to be used as the message body, a 3402 "SUMMARY" property, which contains the text to be used as the message 3403 subject, and one or more "ATTENDEE" properties, which contain the 3404 email address of attendees to receive the message. It can also 3405 include one or more "ATTACH" properties, which are intended to be 3406 sent as message attachments. When the alarm is triggered, the email 3407 message is sent. 3409 When the action is "PROCEDURE", the alarm MUST include one and only 3410 one "ATTACH" property, which MUST point to a procedure resource, 3411 which is invoked when the alarm is triggered. 3413 The "VALARM" calendar component MUST only appear within either a 3414 "VEVENT" or "VTODO" calendar component. "VALARM" calendar components 3415 cannot be nested. Multiple mutually independent "VALARM" calendar 3416 components can be specified for a single "VEVENT" or "VTODO" calendar 3417 component. 3419 The "TRIGGER" property specifies when the alarm will be triggered. 3420 The "TRIGGER" property specifies a duration prior to the start of an 3421 event or a to-do. The "TRIGGER" edge may be explicitly set to be 3422 relative to the "START" or "END" of the event or to-do with the 3423 "RELATED" parameter of the "TRIGGER" property. The "TRIGGER" property 3424 value type can alternatively be set to an absolute calendar date and 3425 time of day value. 3427 In an alarm set to trigger on the "START" of an event or to-do, the 3428 "DTSTART" property MUST be present in the associated event or to-do. 3429 In an alarm in a "VEVENT" calendar component set to trigger on the 3430 "END" of the event, either the "DTEND" property MUST be present, or 3431 the "DTSTART" and "DURATION" properties MUST both be present. In an 3432 alarm in a "VTODO" calendar component set to trigger on the "END" of 3433 the to-do, either the "DUE" property MUST be present, or the 3434 "DTSTART" and "DURATION" properties MUST both be present. 3436 The alarm can be defined such that it triggers repeatedly. A 3437 definition of an alarm with a repeating trigger MUST include both the 3438 "DURATION" and "REPEAT" properties. The "DURATION" property specifies 3439 the delay period, after which the alarm will repeat. The "REPEAT" 3440 property specifies the number of additional repetitions that the 3441 alarm will triggered. This repitition count is in addition to the 3443 Dawson/Stenerson 64 Expires February 1999 3444 initial triggering of the alarm. Both of these properties MUST be 3445 present in order to specify a repeating alarm. If one of these two 3446 properties is absent, then the alarm will not repeat beyond the 3447 initial trigger. 3449 The "ACTION" property is used within the "VALARM" calendar component 3450 to specify the type of action invoked when the alarm is triggered. 3451 The "VALARM" properties provide enough information for a specific 3452 action to be invoked. It is typically the responsibility of a 3453 "Calendar User Agent" (CUA) to deliver the alarm in the specified 3454 fashion. An "ACTION" property value of AUDIO specifies an alarm that 3455 causes a sound to be played to alert the user; DISPLAY specifies an 3456 alarm that causes a text message to be displayed to the user; EMAIL 3457 specifies an alarm that causes an electronic email message to be 3458 delivered to one or more email addresses; and PROCEDURE specifies an 3459 alarm that causes a procedure to be executed. The "ACTION" property 3460 MUST specify one and only one of these values. 3462 In an AUDIO alarm, if the optional "ATTACH" property is included, it 3463 MUST specify an audio sound resource. The intention is that the sound 3464 will be played as the alarm effect. If an "ATTACH" property is 3465 specified that does not refer to a sound resource, or if the 3466 specified sound resource cannot be rendered (because its format is 3467 unsupported, or because it cannot be retrieved), then the CUA or 3468 other entity responsible for playing the sound may choose a fallback 3469 action, such as playing a built-in default sound, or playing no sound 3470 at all. 3472 In a DISPLAY alarm, the intended alarm effect is for the text value 3473 of the "DESCRIPTION" property to be displayed to the user. 3475 In an EMAIL alarm, the intended alarm effect is for an email message 3476 to be composed and delivered to all the addresses specified by the 3477 "ATTENDEE" properties in the "VALARM" calendar component. The 3478 "DESCRIPTION" property of the "VALARM" calendar component MUST be 3479 used as the body text of the message, and the "SUMMARY" property MUST 3480 be used as the subject text. Any "ATTACH" properties in the "VALARM" 3481 calendar component SHOULD be sent as attachments to the message. 3483 In a PROCEDURE alarm, the "ATTACH" property in the "VALARM" calendar 3484 component MUST specify a procedure or program that is intended to be 3485 invoked as the alarm effect. If the procedure or program is in a 3486 format that cannot be rendered, then no procedure alarm will be 3487 invoked. If the "DESCRIPTION" property is present, its value 3488 specifies the argument string to be passed to the procedure or 3489 program. "Calendar User Agents" that receive an iCalendar object with 3490 this category of alarm, can disable or allow the "Calendar User" to 3491 disable, or otherwise ignore this type of alarm. While a very useful 3492 alarm capability, the PROCEDURE type of alarm SHOULD be treated by 3493 the "Calendar User Agent" as a potential security risk. 3495 Example: The following example is for a "VALARM" calendar component 3496 that specifies an audio alarm that will sound at a precise time and 3497 repeat 4 more times at 15 minute intervals: 3499 Dawson/Stenerson 65 Expires February 1999 3500 BEGIN:VALARM 3501 TRIGGER;VALUE=DATE-TIME:19970317T133000Z 3502 REPEAT:4 3503 DURATION:PT15M 3504 ACTION:AUDIO 3505 ATTACH;FMTTYPE=audio/basic:ftp://host.com/pub/sounds/bell-01.aud 3506 END:VALARM 3508 The following example is for a "VALARM" calendar component that 3509 specifies a display alarm that will trigger 30 minutes before the 3510 scheduled start of the event or the due date/time of the to-do it is 3511 associated with and will repeat 2 more times at 15 minute intervals: 3513 BEGIN:VALARM 3514 TRIGGER:-PT30M 3515 REPEAT:2 3516 DURATION:PT15M 3517 ACTION:DISPLAY 3518 DESCRIPTION:Breakfast meeting with executive\n 3519 team at 8:30 AM EST. 3520 END:VALARM 3522 The following example is for a "VALARM" calendar component that 3523 specifies an email alarm that will trigger 2 days before the 3524 scheduled due date/time of a to-do it is associated with. It does not 3525 repeat. The email has a subject, body and attachment link. 3527 BEGIN:VALARM 3528 TRIGGER:-P2D 3529 ACTION:EMAIL 3530 ATTENDEE:MAILTO:john_doe@host.com 3531 SUMMARY:*** REMINDER: SEND AGENDA FOR WEEKLY STAFF MEETING *** 3532 DESCRIPTION:A draft agenda needs to be sent out to the attendees 3533 to the weekly managers meeting (MGR-LIST). Attached is a 3534 pointer the document template for the agenda file. 3535 ATTACH;FMTTYPE=application/binary:http://host.com/templates/agen 3536 da.doc 3537 END:VALARM 3539 The following example is for a "VALARM" calendar component that 3540 specifies a procedural alarm that will trigger at a precise date/time 3541 and will repeat 23 more times at one hour intervals. The alarm will 3542 invoke a procedure file. 3544 BEGIN:VALARM 3545 TRIGGER;VALUE=DATE-TIME:19980101T050000Z 3546 REPEAT:23 3547 DURATION:PT1H 3548 ACTION:PROCEDURE 3549 ATTACH;FMTTYPE=application/binary:ftp://host.com/novo- 3550 procs/felizano.exe 3551 END:VALARM 3553 Dawson/Stenerson 66 Expires February 1999 3554 4.7 Calendar Properties 3556 The Calendar Properties are attributes that apply to the iCalendar 3557 object, as a whole. These properties do not appear within a calendar 3558 component. They SHOULD be specified after the "BEGIN:VCALENDAR" 3559 property and prior to any calendar component. 3561 4.7.1 Calendar Scale 3563 Property Name: CALSCALE 3565 Purpose: This property defines the calendar scale used for the 3566 calendar information specified in the iCalendar object. 3568 Value Type: TEXT 3570 Property Parameters: Non-standard property parameters can be 3571 specified on this property. 3573 Conformance: Property can be specified in an iCalendar object. The 3574 default value is "GREGORIAN". 3576 Description: This memo is based on the Gregorian calendar scale. The 3577 Gregorian calendar scale is assumed if this property is not specified 3578 in the iCalendar object. It is expected that other calendar scales 3579 will be defined in other specifications or by future versions of this 3580 memo. 3582 Format Definition: The property is defined by the following notation: 3584 calscale = "CALSCALE" calparam ":" calvalue CRLF 3586 calparam = *(";" xparam) 3588 calvalue = "GREGORIAN" / iana-token 3590 Example: The following is an example of this property: 3592 CALSCALE:GREGORIAN 3594 4.7.2 Method 3596 Property Name: METHOD 3598 Purpose: This property defines the iCalendar object method associated 3599 with the calendar object. 3601 Value Type: TEXT 3603 Property Parameters: Non-standard property parameters can be 3604 specified on this property. 3606 Conformance: The property can be specified in an iCalendar object. 3608 Dawson/Stenerson 67 Expires February 1999 3609 Description: When used in a MIME message entity, the value of this 3610 property MUST be the same as the Content-Type "method" parameter 3611 value. This property can only appear once within the iCalendar 3612 object. If either the "METHOD" property or the Content-Type "method" 3613 parameter is specified, then the other MUST also be specified. 3615 No methods are defined by this specification. This is the subject of 3616 other specifications, such as the iCalendar Transport-independent 3617 Interoperability Protocol (iTIP) defined by [ITIP]. 3619 If this property is not present in the iCalendar object, then a 3620 scheduling transaction MUST NOT be assumed. In such cases, the 3621 iCalendar object is merely being used to transport a snapshot of some 3622 calendar information; without the intention of conveying a scheduling 3623 semantic. 3625 Format Definition: The property is defined by the following notation: 3627 method = "METHOD" metparam ":" metvalue CRLF 3629 metparam = *(";" xparam) 3631 metvalue = iana-token 3633 Example: The following is a hypothetical example of this property to 3634 convey that the iCalendar object is a request for a meeting: 3636 METHOD:REQUEST 3638 4.7.3 Product Identifier 3640 Property Name: PRODID 3642 Purpose: This property specifies the identifier for the product that 3643 created the iCalendar object. 3645 Value Type: TEXT 3647 Property Parameters: Non-standard property parameters can be 3648 specified on this property. 3650 Conformance: The property MUST be specified once in an iCalendar 3651 object. 3653 Description: The vendor of the implementation SHOULD assure that this 3654 is a globally unique identifier; using some technique such as an FPI 3655 value, as defined in [ISO 9070]. 3657 This property SHOULD not be used to alter the interpretation of an 3658 iCalendar object beyond the semantics specified in this memo. For 3659 example, it is not to be used to further the understanding of non- 3660 standard properties. 3662 Dawson/Stenerson 68 Expires February 1999 3663 Format Definition: The property is defined by the following notation: 3665 prodid = "PRODID" pidparam ":" pidvalue CRLF 3667 pidparam = *(";" xparam) 3669 pidvalue = text 3670 ;Any text that describes the product and version 3671 ;and that is generally assured of being unique. 3673 Example: The following is an example of this property. It does not 3674 imply that English is the default language. 3676 PRODID:-//ABC Corporation//NONSGML My Product//EN 3678 4.7.4 Version 3680 Property Name: VERSION 3682 Purpose: This property specifies the identifier corresponding to the 3683 highest version number or the minimum and maximum range of the 3684 iCalendar specification that is required in order to interpret the 3685 iCalendar object. 3687 Value Type: TEXT 3689 Property Parameters: Non-standard property parameters can be 3690 specified on this property. 3692 Conformance: This property MUST be specified by an iCalendar object, 3693 but MUST only be specified once. 3695 Description: A value of "2.0" corresponds to this memo. 3697 Format Definition: The property is defined by the following notation: 3699 version = "VERSION" verparam ":" vervalue CRLF 3701 verparam = *(";" xparam) 3703 vervalue = "2.0" ;This memo 3704 / maxver 3705 / (minver ";" maxver) 3707 minver = 3708 ;Minimum iCalendar version needed to parse the iCalendar object 3710 maxver = 3711 ;Maximum iCalendar version needed to parse the iCalendar object 3713 Example: The following is an example of this property: 3715 VERSION:2.0 3717 Dawson/Stenerson 69 Expires February 1999 3718 4.8 Component Properties 3720 The following properties can appear within calendar components, as 3721 specified by each component property definition. 3723 4.8.1 Descriptive Component Properties 3725 The following properties specify descriptive information about 3726 calendar components. 3728 4.8.1.1 Attachment 3730 Property Name: ATTACH 3732 Purpose: The property provides the capability to associate a document 3733 object with a calendar component. 3735 Value Type: The default value type for this property is URI. The 3736 value type can also be set to BINARY to indicate inline binary 3737 encoded content information. 3739 Property Parameters: Non-standard, inline encoding, format type and 3740 value data type property parameters can be specified on this 3741 property. 3743 Conformance: The property can be specified in a "VEVENT", "VTODO", 3744 "VJOURNAL" or "VALARM" calendar components. 3746 Description: The property can be specified within "VEVENT", "VTODO", 3747 "VJOURNAL", or "VALARM" calendar components. This property can be 3748 specified multiple times within an iCalendar object. 3750 Format Definition: The property is defined by the following notation: 3752 attach = "ATTACH" attparam ":" uri CRLF 3754 attach =/ "ATTACH" attparam ";" "ENCODING" "=" "BASE64" 3755 ";" "VALUE" "=" "BINARY" ":" binary 3757 attparam = *( 3759 ; the following is optional, 3760 ; but MUST NOT occur more than once 3762 (";" fmttypeparam) / 3764 ; the following is optional, 3765 ; and MAY occur more than once 3767 (";" xparam) 3769 ) 3771 Dawson/Stenerson 70 Expires February 1999 3772 Example: The following are examples of this property: 3774 ATTACH:CID:jsmith.part3.960817T083000.xyzMail@host1.com 3776 ATTACH;FMTTYPE=application/postscript:ftp://xyzCorp.com/pub/ 3777 reports/r-960812.ps 3779 4.8.1.2 Categories 3781 Property Name: CATEGORIES 3783 Purpose: This property defines the categories for a calendar 3784 component. 3786 Value Type: TEXT 3788 Property Parameters: Non-standard and language property parameters 3789 can be specified on this property. 3791 Conformance: The property can be specified within "VEVENT", "VTODO" 3792 or "VJOURNAL" calendar components. 3794 Description: This property is used to specify categories or subtypes 3795 of the calendar component. The categories are useful in searching for 3796 a calendar component of a particular type and category. Within the 3797 "VEVENT", "VTODO" or "VJOURNAL" calendar components, more than one 3798 category can be specified as a list of categories separated by the 3799 COMMA character (US-ASCII decimal 44). 3801 Format Definition: The property is defined by the following notation: 3803 categories = "CATEGORIES" catparam ":" text *("," text) 3804 CRLF 3806 catparam = *( 3808 ; the following is optional, 3809 ; but MUST NOT occur more than once 3811 (";" languageparam ) / 3813 ; the following is optional, 3814 ; and MAY occur more than once 3816 (";" xparam) 3818 ) 3820 Example: The following are examples of this property: 3822 CATEGORIES:APPOINTMENT,EDUCATION 3824 CATEGORIES:MEETING 3826 Dawson/Stenerson 71 Expires February 1999 3827 4.8.1.3 Classification 3829 Property Name: CLASS 3831 Purpose: This property defines the access classification for a 3832 calendar component. 3834 Value Type: TEXT 3836 Property Parameters: Non-standard property parameters can be 3837 specified on this property. 3839 Conformance: The property can be specified once in a "VEVENT", 3840 "VTODO" or "VJOURNAL" calendar components. 3842 Description: An access classification is only one component of the 3843 general security system within a calendar application. It provides a 3844 method of capturing the scope of the access the calendar owner 3845 intends for information within an individual calendar entry. The 3846 access classification of an individual iCalendar component is useful 3847 when measured along with the other security components of a calendar 3848 system (e.g., calendar user authentication, authorization, access 3849 rights, access role, etc.). Hence, the semantics of the individual 3850 access classifications cannot be completely defined by this memo 3851 alone. Additionally, due to the "blind" nature of most exchange 3852 processes using this memo, these access classifications cannot serve 3853 as an enforcement statement for a system receiving an iCalendar 3854 object. Rather, they provide a method for capturing the intention of 3855 the calendar owner for the access to the calendar component. The 3856 [ICMS] provides a broader description of the security system within a 3857 calendar application. 3859 Format Definition: The property is defined by the following notation: 3861 class = "CLASS" classparam ":" classvalue CRLF 3863 classparam = *(";" xparam) 3865 classvalue = "PUBLIC" / "PRIVATE" / "CONFIDENTIAL" / iana-token 3866 / x-name 3867 ;Default is PUBLIC 3869 Example: The following is an example of this property: 3871 CLASS:PUBLIC 3873 4.8.1.4 Comment 3875 Property Name: COMMENT 3877 Purpose: This property specifies non-processing information intended 3878 to provide a comment to the calendar user. 3880 Dawson/Stenerson 72 Expires February 1999 3881 Value Type: TEXT 3883 Property Parameters: Non-standard, alternate text representation and 3884 language property parameters can be specified on this property. 3886 Conformance: This property can be specified in "VEVENT", "VTODO", 3887 "VJOURNAL", "VTIMEZONE" or "VFREEBUSY" calendar components. 3889 Description: The property can be specified multiple times. 3891 Format Definition: The property is defined by the following notation: 3893 comment = "COMMENT" commparam ":" text CRLF 3895 commparam = *( 3897 ; the following are optional, 3898 ; but MUST NOT occur more than once 3900 (";" altrepparam) / (";" languageparam) / 3902 ; the following is optional, 3903 ; and MAY occur more than once 3905 (";" xparam) 3907 ) 3909 Example: The following is an example of this property: 3911 COMMENT:The meeting really needs to include both ourselves 3912 and the customer. We can�t hold this meeting without them. 3913 As a matter of fact\, the venue for the meeting ought to be at 3914 their site. - - John 3916 The data type for this property is TEXT. 3918 4.8.1.5 Description 3920 Property Name: DESCRIPTION 3922 Purpose: This property provides a more complete description of the 3923 calendar component, than that provided by the "SUMMARY" property. 3925 Value Type: TEXT 3927 Property Parameters: Non-standard, alternate text representation and 3928 language property parameters can be specified on this property. 3930 Conformance: The property can be specified in the "VEVENT", "VTODO", 3931 "VJOURNAL" or "VALARM" calendar components. The property can be 3932 specified multiple times only within a "VJOURNAL" calendar component. 3934 Dawson/Stenerson 73 Expires February 1999 3935 Description: This property is used in the "VEVENT" and "VTODO" to 3936 capture lengthy textual decriptions associated with the activity. 3938 This property is used in the "VJOURNAL" calendar component to capture 3939 one more textual journal entries. 3941 This property is used in the "VALARM" calendar component to capture 3942 the display text for a DISPLAY category of alarm, to capture the body 3943 text for an EMAIL category of alarm and to capture the argument 3944 string for a PROCEDURE category of alarm. 3946 Format Definition: The property is defined by the following notation: 3948 description = "DESCRIPTION" descparam ":" text CRLF 3950 descparam = *( 3952 ; the following are optional, 3953 ; but MUST NOT occur more than once 3955 (";" altrepparam) / (";" languageparam) / 3957 ; the following is optional, 3958 ; and MAY occur more than once 3960 (";" xparam) 3962 ) 3964 Example: The following is an example of the property with formatted 3965 line breaks in the property value: 3967 DESCRIPTION:Meeting to provide technical review for "Phoenix" 3968 design.\n Happy Face Conference Room. Phoenix design team 3969 MUST attend this meeting.\n RSVP to team leader. 3971 The following is an example of the property with folding of long 3972 lines: 3974 DESCRIPTION:Last draft of the new novel is to be completed 3975 for the editor�s proof today. 3977 4.8.1.6 Geographic Position 3979 Property Name: GEO 3981 Purpose: This property specifies information related to the global 3982 position for the activity specified by a calendar component. 3984 Value Type: FLOAT. The value MUST be two SEMICOLON separated FLOAT 3985 values. 3987 Dawson/Stenerson 74 Expires February 1999 3988 Property Parameters: Non-standard property parameters can be 3989 specified on this property. 3991 Conformance: This property can be specified in "VEVENT" or "VTODO" 3992 calendar components.. 3994 Description: The property value specifies latitude and longitude, in 3995 that order (i.e., "LAT LON" ordering). The longitude represents the 3996 location east or west of the prime meridian as a positive or negative 3997 real number, respectively. The longitude and latitude values MAY be 3998 specified up to six decimal places, which will allow for accuracy to 3999 within one meter of geographical position. Receiving applications 4000 MUST accept values of this precision and MAY truncate values of 4001 greater precision. 4003 Values for latitude and longitude shall be expressed as decimal 4004 fractions of degrees. Whole degrees of latitude shall be represented 4005 by a two-digit decimal number ranging from 0 through 90. Whole 4006 degrees of longitude shall be represented by a decimal number ranging 4007 from 0 through 180. When a decimal fraction of a degree is specified, 4008 it shall be separated from the whole number of degrees by a decimal 4009 point. 4011 Latitudes north of the equator shall be specified by a plus sign (+), 4012 or by the absence of a minus sign (-), preceding the digits 4013 designating degrees. Latitudes south of the Equator shall be 4014 designated by a minus sign (-) preceding the digits designating 4015 degrees. A point on the Equator shall be assigned to the Northern 4016 Hemisphere. 4018 Longitudes east of the prime meridian shall be specified by a plus 4019 sign (+), or by the absence of a minus sign (-), preceding the digits 4020 designating degrees. Longitudes west of the meridian shall be 4021 designated by minus sign (-) preceding the digits designating 4022 degrees. A point on the prime meridian shall be assigned to the 4023 Eastern Hemisphere. A point on the 180th meridian shall be assigned 4024 to the Western Hemisphere. One exception to this last convention is 4025 permitted. For the special condition of describing a band of latitude 4026 around the earth, the East Bounding Coordinate data element shall be 4027 assigned the value +180 (180) degrees. 4029 Any spatial address with a latitude of +90 (90) or -90 degrees will 4030 specify the position at the North or South Pole, respectively. The 4031 component for longitude may have any legal value. 4033 With the exception of the special condition described above, this 4034 form is specified in Department of Commerce, 1986, Representation of 4035 geographic point locations for information interchange (Federal 4036 Information Processing Standard 70-1): Washington, Department of 4037 Commerce, National Institute of Standards and Technology. 4039 The simple formula for converting degrees-minutes-seconds into 4040 decimal degrees is: 4041 decimal = degrees + minutes/60 + seconds/3600. 4043 Dawson/Stenerson 75 Expires February 1999 4044 Format Definition: The property is defined by the following notation: 4046 geo = "GEO" geoparam ":" geovalue CRLF 4048 geoparam = *(";" xparam) 4050 geovalue = float ";" float 4051 ;Latitude and Longitude components 4053 Example: The following is an example of this property: 4055 GEO:37.386013;-122.082932 4057 4.8.1.7 Location 4059 Property Name: LOCATION 4061 Purpose: The property defines the intended venue for the activity 4062 defined by a calendar component. 4064 Value Type: TEXT 4066 Property Parameters: Non-standard, alternate text representation and 4067 language property parameters can be specified on this property. 4069 Conformance: This property can be specified in "VEVENT" or "VTODO" 4070 calendar component. 4072 Description: Specific venues such as conference or meeting rooms may 4073 be explicitly specified using this property. An alternate 4074 representation may be specified that is a URI that points to 4075 directory information with more structured specification of the 4076 location. For example, the alternate representation may specify 4077 either an LDAP URI pointing to an LDAP server entry or a CID URI 4078 pointing to a MIME body part containing a vCard for the location. 4080 Format Definition: The property is defined by the following notation: 4082 location = "LOCATION locparam ":" text CRLF 4084 locparam = *( 4086 ; the following are optional, 4087 ; but MUST NOT occur more than once 4089 (";" altrepparam) / (";" languageparam) / 4091 ; the following is optional, 4092 ; and MAY occur more than once 4094 (";" xparam) 4096 ) 4098 Dawson/Stenerson 76 Expires February 1999 4099 Example: The following are some examples of this property: 4101 LOCATION:Conference Room - F123, Bldg. 002 4103 LOCATION;ALTREP="http://xyzcorp.com/conf-rooms/f123.vcf": 4104 Conference Room - F123, Bldg. 002 4106 4.8.1.8 Percent Complete 4108 Property Name: PERCENT-COMPLETE 4110 Purpose: This property is used by an assignee or delegatee of a to-do 4111 to convey the percent completion of a to-do to the Organizer. 4113 Value Type: INTEGER 4115 Property Parameters: Non-standard property parameters can be 4116 specified on this property. 4118 Conformance: This property can be specified in a "VTODO" calendar 4119 component. 4121 Description: The property value is a positive integer between zero 4122 and one hundred. A value of "0" indicates the to-do has not yet been 4123 started. A value of "100" indicates that the to-do has been 4124 completed. Integer values in between indicate the percent partially 4125 complete. 4127 When a to-do is assigned to multiple individuals, the property value 4128 indicates the percent complete for that portion of the to-do assigned 4129 to the assignee or delegatee. For example, if a to-do is assigned to 4130 both individuals "A" and "B". A reply from "A" with a percent 4131 complete of "70" indicates that "A" has completed 70% of the to-do 4132 assigned to them. A reply from "B" with a percent complete of "50" 4133 indicates "B" has completed 50% of the to-do assigned to them. 4135 Format Definition: The property is defined by the following notation: 4137 percent = "PERCENT-COMPLETE" pctparam ":" integer CRLF 4139 pctparam = *(";" xparam) 4141 Example: The following is an example of this property to show 39% 4142 completion: 4144 PERCENT-COMPLETE:39 4146 4.8.1.9 Priority 4148 Property Name: PRIORITY 4150 Purpose: The property defines the relative priority for a calendar 4151 component. 4153 Dawson/Stenerson 77 Expires February 1999 4154 Value Type: INTEGER 4156 Property Parameters: Non-standard property parameters can be 4157 specified on this property. 4159 Conformance: The property can be specified in a "VEVENT" or "VTODO" 4160 calendar component. 4162 Description: The priority is specified as an integer in the range 4163 zero to nine. A value of zero (US-ASCII decimal 48) specifies an 4164 undefined priority. A value of one (US-ASCII decimal 49) is the 4165 highest priority. A value of two (US-ASCII decimal 50) is the second 4166 highest priority. Subsequent numbers specify a decreasing ordinal 4167 priority. A value of nine (US-ASCII decimal 58) is the lowest 4168 priority. 4170 A CUA with a three-level priority scheme of "HIGH", "MEDIUM" and 4171 "LOW" is mapped into this property such that a property value in the 4172 range of one (US-ASCII decimal 49) to four (US-ASCII decimal 52) 4173 specifies "HIGH" priority. A value of five (US-ASCII decimal 53) is 4174 the normal or "MEDIUM" priority. A value in the range of six (US- 4175 ASCII decimal 54) to nine (US-ASCII decimal 58) is "LOW" priority. 4177 A CUA with a priority schema of "A1", "A2", "A3", "B1", "B2", ..., 4178 "C3" is mapped into this property such that a property value of one 4179 (US-ASCII decimal 49) specifies "A1", a property value of two (US- 4180 ASCII decimal 50) specifies "A2", a property value of three (US-ASCII 4181 decimal 51) specifies "A3", and so forth up to a property value of 9 4182 (US-ASCII decimal 58) specifies "C3". 4184 Other integer values are reserved for future use. 4186 Within a "VEVENT" calendar component, this property specifies a 4187 priority for the event. This property may be useful when more than 4188 one event is scheduled for a given time period. 4190 Within a "VTODO" calendar component, this property specified a 4191 priority for the to-do. This property is useful in prioritizing 4192 multiple action items for a given time period. 4194 Format Definition: The property is specified by the following 4195 notation: 4197 priority = "PRIORITY" prioparam ":" privalue CRLF 4198 ;Default is zero 4200 prioparam = *(";" xparam) 4202 privalue = integer ;Must be in the range [0..9] 4203 ; All other values are reserved for future use 4205 The following is an example of a property with the highest priority: 4207 PRIORITY:1 4209 Dawson/Stenerson 78 Expires February 1999 4210 The following is an example of a property with a next highest 4211 priority: 4213 PRIORITY:2 4215 Example: The following is an example of a property with no priority. 4216 This is equivalent to not specifying the "PRIORITY" property: 4218 PRIORITY:0 4220 4.8.1.10 Resources 4222 Property Name: RESOURCES 4224 Purpose: This property defines the equipment or resources anticipated 4225 for an activity specified by a calendar entity.. 4227 Value Type: TEXT 4229 Property Parameters: Non-standard, alternate text representation and 4230 language property parameters can be specified on this property. 4232 Conformance: This property can be specified in "VEVENT" or "VTODO" 4233 calendar component. 4235 Description: The property value is an arbitrary text. More than one 4236 resource can be specified as a list of resources separated by the 4237 COMMA character (US-ASCII decimal 44). 4239 Format Definition: The property is defined by the following notation: 4241 resources = "RESOURCES" resrcparam ":" text *("," text) CRLF 4243 resrcparam = *( 4245 ; the following are optional, 4246 ; but MUST NOT occur more than once 4248 (";" altrepparam) / (";" languageparam) / 4250 ; the following is optional, 4251 ; and MAY occur more than once 4253 (";" xparam) 4255 ) 4257 Example: The following is an example of this property: 4259 RESOURCES:EASEL,PROJECTOR,VCR 4261 RESOURCES;LANGUAGE=fr:1 raton-laveur 4263 Dawson/Stenerson 79 Expires February 1999 4264 4.8.1.11 Status 4266 Property Name: STATUS 4268 Purpose: This property defines the overall status or confirmation for 4269 the calendar component. 4271 Value Type: TEXT 4273 Property Parameters: Non-standard property parameters can be 4274 specified on this property. 4276 Conformance: This property can be specified in "VEVENT", "VTODO" or 4277 "VJOURNAL" calendar components. 4279 Description: In a group scheduled calendar component, the property is 4280 used by the "Organizer" to provide a confirmation of the event to the 4281 "Attendees". For example in a "VEVENT" calendar component, the 4282 "Organizer" can indicate that a meeting is tentative, confirmed or 4283 cancelled. In a "VTODO" calendar component, the "Organizer" can 4284 indicate that an action item needs action, is completed, is in 4285 process or being worked on, or has been cancelled. In a "VJOURNAL" 4286 calendar component, the "Organizer" can indicate that a journal entry 4287 is draft, final or has been cancelled or removed. 4289 Format Definition: The property is defined by the following notation: 4291 status = "STATUS" statparam] ":" statvalue CRLF 4293 statparam = *(";" xparam) 4295 statvalue = "TENTATIVE" ;Indicates event is 4296 ;tentative. 4297 / "CONFIRMED" ;Indicates event is 4298 ;definite. 4299 / "CANCELLED" ;Indicates event was 4300 ;cancelled. 4301 ;Status values for a "VEVENT" 4303 statvalue =/ "NEEDS-ACTION" ;Indicates to-do needs action. 4304 / "COMPLETED" ;Indicates to-do completed. 4305 / "IN-PROCESS" ;Indicates to-do in process of 4306 / "CANCELLED" ;Indicates to-do was cancelled. 4307 ;Status values for "VTODO". 4309 statvalue =/ "DRAFT" ;Indicates journal is draft. 4310 / "FINAL" ;Indicates journal is final. 4311 / "CANCELLED" ;Indicates journal is removed. 4312 ;Status values for "VJOURNAL". 4314 Example: The following is an example of this property for a "VEVENT" 4315 calendar component: 4317 Dawson/Stenerson 80 Expires February 1999 4318 STATUS:TENTATIVE 4320 The following is an example of this property for a "VTODO" calendar 4321 component: 4323 STATUS:NEEDS-ACTION 4325 The following is an example of this property for a "VJOURNAL" 4326 calendar component: 4328 STATUS:DRAFT 4330 4.8.1.12 Summary 4332 Property Name: SUMMARY 4334 Purpose: This property defines a short summary or subject for the 4335 calendar component. 4337 Value Type: TEXT 4339 Property Parameters: Non-standard, alternate text representation and 4340 language property parameters can be specified on this property. 4342 Conformance: The property can be specified in "VEVENT", "VTODO", 4343 "VJOURNAL" or "VALARM" calendar components. 4345 Description: This property is used in the "VEVENT", "VTODO" and 4346 "VJOURNAL" calendar components to capture a short, one line summary 4347 about the activity or journal entry. 4349 This property is used in the "VALARM" calendar component to capture 4350 the subject of an EMAIL category of alarm. 4352 Format Definition: The property is defined by the following notation: 4354 summary = "SUMMARY" summparam ":" text CRLF 4356 summparam = *( 4358 ; the following are optional, 4359 ; but MUST NOT occur more than once 4361 (";" altrepparam) / (";" languageparam) / 4363 ; the following is optional, 4364 ; and MAY occur more than once 4366 (";" xparam) 4368 ) 4370 Example: The following is an example of this property: 4372 Dawson/Stenerson 81 Expires February 1999 4373 SUMMARY:Department Party 4375 4.8.2 Date and Time Component Properties 4377 The following properties specify date and time related information in 4378 calendar components. 4380 4.8.2.1 Date/Time Completed 4382 Property Name: COMPLETED 4384 Purpose: This property defines the date and time that a to-do was 4385 actually completed. 4387 Value Type: DATE-TIME 4389 Property Parameters: Non-standard property parameters can be 4390 specified on this property. 4392 Conformance: The property can be specified in a "VTODO" calendar 4393 component. 4395 Description: The date and time MUST be in a UTC format. 4397 Format Definition: The property is defined by the following notation: 4399 completed = "COMPLETED" compparam ":" date-time CRLF 4401 compparam = *(";" xparam) 4403 Example: The following is an example of this property: 4405 COMPLETED:19960401T235959Z 4407 4.8.2.2 Date/Time End 4409 Property Name: DTEND 4411 Purpose: This property specifies the date and time that a calendar 4412 component ends. 4414 Value Type: The default value type is DATE-TIME. The value type can 4415 be set to a DATE value type. 4417 Property Parameters: Non-standard, value data type, time zone 4418 identifier property parameters can be specified on this property. 4420 Conformance: This property can be specified in "VEVENT" or 4421 "VFREEBUSY" calendar components. 4423 Description: Within the "VEVENT" calendar component, this property 4424 defines the date and time by which the event ends. The value MUST be 4425 later in time than the value of the "DTSTART" property. 4427 Dawson/Stenerson 82 Expires February 1999 4428 Within the "VFREEBUSY" calendar component, this property defines the 4429 end date and time for the free or busy time information. The time 4430 MUST be specified in the UTC time format. The value MUST be later in 4431 time than the value of the "DTSTART" property. 4433 Format Definition: The property is defined by the following notation: 4435 dtend = "DTEND" dtendparam":" dtendval CRLF 4437 dtendparam = *( 4439 ; the following are optional, 4440 ; but MUST NOT occur more than once 4442 (";" "VALUE" "=" ("DATE-TIME" / "DATE")) / 4443 (";" tzidparam) / 4445 ; the following is optional, 4446 ; and MAY occur more than once 4448 (";" xparam) 4450 ) 4452 dtendval = date-time / date 4453 ;Value MUST match value type 4455 Example: The following is an example of this property: 4457 DTEND:19960401T235959Z 4459 DTEND;VALUE=DATE:19980704 4461 4.8.2.3 Date/Time Due 4463 Property Name: DUE 4465 Purpose: This property defines the date and time that a to-do is 4466 expected to be completed. 4468 Value Type: The default value type is DATE-TIME. The value type can 4469 be set to a DATE value type. 4471 Property Parameters: Non-standard, value data type, time zone 4472 identifier property parameters can be specified on this property. 4474 Conformance: The property can be specified once in a "VTODO" calendar 4475 component. 4477 Description: The value MUST be a date/time equal to or after the 4478 DTSTART value, if specified. 4480 Dawson/Stenerson 83 Expires February 1999 4481 Format Definition: The property is defined by the following notation: 4483 due = "DUE" dueparam":" dueval CRLF 4485 dueparam = *( 4487 ; the following are optional, 4488 ; but MUST NOT occur more than once 4490 (";" "VALUE" "=" ("DATE-TIME" / "DATE")) / 4491 (";" tzidparam) / 4493 ; the following is optional, 4494 ; and MAY occur more than once 4496 *(";" xparam) 4498 ) 4500 dueval = date-time / date 4501 ;Value MUST match value type 4503 Example: The following is an example of this property: 4505 DUE:19980430T235959Z 4507 4.8.2.4 Date/Time Start 4509 Property Name: DTSTART 4511 Purpose: This property specifies when the calendar component begins. 4513 Value Type: The default value type is DATE-TIME. The time value MUST 4514 be one of the forms defined for the DATE-TIME value type. The value 4515 type can be set to a DATE value type. 4517 Property Parameters: Non-standard, value data type, time zone 4518 identifier property parameters can be specified on this property. 4520 Conformance: This property can be specified in the "VEVENT", "VTODO", 4521 "VFREEBUSY", or "VTIMEZONE" calendar components. 4523 Description: Within the "VEVENT" calendar component, this property 4524 defines the start date and time for the event. The property is 4525 REQUIRED in "VEVENT" calendar components. Events can have a start 4526 date/time but no end date/time. In that case, the event does not take 4527 up any time. 4529 Within the "VFREEBUSY" calendar component, this property defines the 4530 start date and time for the free or busy time information. The time 4531 MUST be specified in UTC time. 4533 Dawson/Stenerson 84 Expires February 1999 4534 Within the "VTIMEZONE" calendar component, this property defines the 4535 effective start date and time for a time zone specification. This 4536 property is REQUIRED within each STANDARD and DAYLIGHT part included 4537 in "VTIMEZONE" calendar components and MUST be specified as a local 4538 DATE-TIME without the "TZID" property parameter. 4540 Format Definition: The property is defined by the following notation: 4542 dtstart = "DTSTART" dtstparam ":" dtstval CRLF 4544 dtstparam = *( 4546 ; the following are optional, 4547 ; but MUST NOT occur more than once 4549 (";" "VALUE" "=" ("DATE-TIME" / "DATE")) / 4550 (";" tzidparam) / 4552 ; the following is optional, 4553 ; and MAY occur more than once 4555 *(";" xparam) 4557 ) 4559 dtstval = date-time / date 4560 ;Value MUST match value type 4562 Example: The following is an example of this property: 4564 DTSTART:19980118T073000Z 4566 4.8.2.5 Duration 4568 Property Name: DURATION 4570 Purpose: The property specifies a positive duration of time . 4572 Value Type: DURATION 4574 Property Parameters: Non-standard property parameters can be 4575 specified on this property. 4577 Conformance: The property can be specified in "VEVENT", "VTODO", 4578 "VFREEBUSY" or "VALARM" calendar components. 4580 Description: In a "VEVENT" calendar component the property may be 4581 used to specify a duration of the event, instead of an explicit end 4582 date/time. In a "VTODO" calendar component the property may be used 4583 to specify a duration for the to-do, instead of an explicit due 4584 date/time. In a "VFREEBUSY" calendar component the property may be 4586 Dawson/Stenerson 85 Expires February 1999 4587 used to specify the interval of free time being requested. In a 4588 "VALARM" calendar component the property may be used to specify the 4589 delay period prior to repeating an alarm. 4591 Format Definition: The property is defined by the following notation: 4593 duration = "DURATION" durparam ":" dur-value CRLF 4594 ;consisting of a positive duration of time. 4596 durparam = *(";" xparam) 4598 Example: The following is an example of this property that specifies 4599 an interval of time of 1 hour and zero minutes and zero seconds: 4601 DURATION:PT1H0M0S 4603 The following is an example of this property that specifies an 4604 interval of time of 15 minutes. 4606 DURATION:PT15M 4608 4.8.2.6 Free/Busy Time 4610 Property Name: FREEBUSY 4612 Purpose: The property defines one or more free or busy time 4613 intervals. 4615 Value Type: PERIOD. The date and time values MUST be in an UTC time 4616 format. 4618 Property Parameters: Non-standard or free/busy time type property 4619 parameters can be specified on this property. 4621 Conformance: The property can be specified in a "VFREEBUSY" calendar 4622 component. 4624 Property Parameter: "FBTYPE" and non-standard parameters can be 4625 specified on this property. 4627 Description: These time periods can be specified as either a start 4628 and end date-time or a start date-time and duration. The date and 4629 time MUST be a UTC time format. 4631 "FREEBUSY" properties within the "VFREEBUSY" calendar component 4632 SHOULD be sorted in ascending order, based on start time and then end 4633 time, with the earliest periods first. 4635 The "FREEBUSY" property can specify more than one value, separated by 4636 the COMMA character (US-ASCII decimal 44). In such cases, the 4637 "FREEBUSY" property values SHOULD all be of the same "FBTYPE" 4638 property parameter type (e.g., all values of a particular "FBTYPE" 4639 listed together in a single property). 4641 Dawson/Stenerson 86 Expires February 1999 4642 Format Definition: The property is defined by the following notation: 4644 freebusy = "FREEBUSY" fbparam ":" fbvalue 4645 CRLF 4647 fbparam = *( 4649 ; the following is optional, 4650 ; but MUST NOT occur more than once 4652 (";" fbtypeparam) / 4654 ; the following is optional, 4655 ; and MAY occur more than once 4657 (";" xparam) 4659 ) 4661 fbvalue = period *["," period] 4662 ;Time value MUST be in the UTC time format. 4664 Example: The following are some examples of this property: 4666 FREEBUSY;FBTYPE=BUSY-UNAVAILABLE:19970308T160000Z/PT8H30M 4668 FREEBUSY;FBTYPE=FREE:19970308T160000Z/PT3H,19970308T200000Z/PT1H 4670 FREEBUSY;FBTYPE=FREE:19970308T160000Z/PT3H,19970308T200000Z/PT1H, 4671 19970308T230000Z/19970309T000000Z 4673 4.8.2.7 Time Transparency 4675 Property Name: TRANSP 4677 Purpose: This property defines whether an event is transparent or not 4678 to busy time searches. 4680 Value Type: TEXT 4682 Property Parameters: Non-standard property parameters can be 4683 specified on this property. 4685 Conformance: This property can be specified once in a "VEVENT" 4686 calendar component. 4688 Description: Time Transparency is the characteristic of an event that 4689 determines whether it appears to consume time on a calendar. Events 4690 that consume actual time for the individual or resource associated 4691 with the calendar SHOULD be recorded as OPAQUE, allowing them to be 4692 detected by free-busy time searches. Other events, which do not take 4693 up the individual's (or resource's) time SHOULD be recorded as 4694 TRANSPARENT, making them invisible to free-busy time searches. 4696 Dawson/Stenerson 87 Expires February 1999 4697 Format Definition: The property is specified by the following 4698 notation: 4700 transp = "TRANSP" tranparam ":" transvalue CRLF 4702 tranparam = *(";" xparam) 4704 transvalue = "OPAQUE" ;Blocks or opaque on busy time searches. 4705 / "TRANSPARENT" ;Transparent on busy time searches. 4706 ;Default value is OPAQUE 4708 Example: The following is an example of this property for an event 4709 that is transparent or does not block on free/busy time searches: 4711 TRANSP:TRANSPARENT 4713 The following is an example of this property for an event that is 4714 opaque or blocks on free/busy time searches: 4716 TRANSP:OPAQUE 4718 4.8.3 Time Zone Component Properties 4720 The following properties specify time zone information in calendar 4721 components. 4723 4.8.3.1 Time Zone Identifier 4725 Property Name: TZID 4727 Purpose: This property specifies the text value that uniquely 4728 identifies the "VTIMEZONE" calendar component. 4730 Value Type: TEXT 4732 Property Parameters: Non-standard property parameters can be 4733 specified on this property. 4735 Conformance: This property MUST be specified in a "VTIMEZONE" 4736 calendar component. 4738 Description: This is the label by which a time zone calendar 4739 component is referenced by any iCalendar properties whose data type 4740 is either DATE-TIME or TIME and not intended to specify a UTC or a 4741 "floating" time. The presence of the SOLIDUS character (US-ASCII 4742 decimal 47) as a prefix, indicates that this TZID represents an 4743 unique ID in a globally defined time zone registry (when such 4744 registry is defined). 4746 Note: This document does not define a naming convention for time 4747 zone identifiers. Implementers may want to use the naming 4748 conventions defined in existing time zone specifications such as 4749 the public-domain Olson database [TZ]. The specification of 4751 Dawson/Stenerson 88 Expires February 1999 4752 globally unique time zone identifiers is not addressed by this 4753 document and is left for future study. 4755 Format Definition: This property is defined by the following 4756 notation: 4758 tzid = "TZID" tzidpropparam ":" [tzidprefix] text CRLF 4760 tzidpropparam = *(";" xparam) 4762 ;tzidprefix = "/" 4763 ; Defined previously. Just listed here for reader convenience. 4765 Example: The following are examples of non-globally unique time zone 4766 identifiers: 4768 TZID:US-Eastern 4770 TZID:California-Los_Angeles 4772 The following is an example of a fictitious globally unique time zone 4773 identifier: 4775 TZID:/US-New_York-New_York 4777 4.8.3.2 Time Zone Name 4779 Property Name: TZNAME 4781 Purpose: This property specifies the customary designation for a time 4782 zone description. 4784 Value Type: TEXT 4786 Property Parameters: Non-standard and language property parameters 4787 can be specified on this property. 4789 Conformance: This property can be specified in a "VTIMEZONE" calendar 4790 component. 4792 Description: This property may be specified in multiple languages; in 4793 order to provide for different language requirements. 4795 Format Definition: This property is defined by the following 4796 notation: 4798 tzname = "TZNAME" tznparam ":" text CRLF 4800 tznparam = *( 4802 ; the following is optional, 4803 ; but MUST NOT occur more than once 4805 Dawson/Stenerson 89 Expires February 1999 4806 (";" languageparam) / 4808 ; the following is optional, 4809 ; and MAY occur more than once 4811 (";" xparam) 4813 ) 4815 Example: The following are example of this property: 4817 TZNAME:EST 4819 The following is an example of this property when two different 4820 languages for the time zone name are specified: 4822 TZNAME;LANGUAGE=en:EST 4823 TZNAME;LANGUAGE=fr-CA:HNE 4825 4.8.3.3 Time Zone Offset From 4827 Property Name: TZOFFSETFROM 4829 Purpose: This property specifies the offset which is in use prior to 4830 this time zone observance. 4832 Value Type: UTC-OFFSET 4834 Property Parameters: Non-standard property parameters can be 4835 specified on this property. 4837 Conformance: This property MUST be specified in a "VTIMEZONE" 4838 calendar component. 4840 Description: This property specifies the offset which is in use prior 4841 to this time observance. It is used to calculate the absolute time at 4842 which the transition to a given observance takes place. This property 4843 MUST only be specified in a "VTIMEZONE" calendar component. A 4844 "VTIMEZONE" calendar component MUST include this property. The 4845 property value is a signed numeric indicating the number of hours and 4846 possibly minutes from UTC. Positive numbers represent time zones east 4847 of the prime meridian, or ahead of UTC. Negative numbers represent 4848 time zones west of the prime meridian, or behind UTC. 4850 Format Definition: The property is defined by the following notation: 4852 tzoffsetfrom = "TZOFFSETFROM" frmparam ":" utc-offset 4853 CRLF 4855 frmparam = *(";" xparam) 4857 Example: The following are examples of this property: 4859 Dawson/Stenerson 90 Expires February 1999 4860 TZOFFSETFROM:-0500 4862 TZOFFSETFROM:+1345 4864 4.8.3.4 Time Zone Offset To 4866 Property Name: TZOFFSETTO 4868 Purpose: This property specifies the offset which is in use in this 4869 time zone observance. 4871 Value Type: UTC-OFFSET 4873 Property Parameters: Non-standard property parameters can be 4874 specified on this property. 4876 Conformance: This property MUST be specified in a "VTIMEZONE" 4877 calendar component. 4879 Description: This property specifies the offset which is in use in 4880 this time zone observance. It is used to calculate the absolute time 4881 for the new observance. The property value is a signed numeric 4882 indicating the number of hours and possibly minutes from UTC. 4883 Positive numbers represent time zones east of the prime meridian, or 4884 ahead of UTC. Negative numbers represent time zones west of the prime 4885 meridian, or behind UTC. 4887 Format Definition: The property is defined by the following notation: 4889 tzoffsetto = "TZOFFSETTO" toparam ":" utc-offset CRLF 4891 toparam = *(";" xparam) 4893 Example: The following are examples of this property: 4895 TZOFFSETTO:-0400 4897 TZOFFSETTO:+1245 4899 4.8.3.5 Time Zone URL 4901 Property Name: TZURL 4903 Purpose: The TZURL provides a means for a VTIMEZONE component to 4904 point to a network location that can be used to retrieve an up-to- 4905 date version of itself. 4907 Value Type: URI 4909 Property Parameters: Non-standard property parameters can be 4910 specified on this property. 4912 Dawson/Stenerson 91 Expires February 1999 4913 Conformance: This property can be specified in a "VTIMEZONE" calendar 4914 component. 4916 Description: The TZURL provides a means for a VTIMEZONE component to 4917 point to a network location that can be used to retrieve an up-to- 4918 date version of itself. This provides a hook to handle changes 4919 government bodies impose upon time zone definitions. Retrieval of 4920 this resource results in an iCalendar object containing a single 4921 VTIMEZONE component and a METHOD property set to PUBLISH. 4923 Format Definition: The property is defined by the following notation: 4925 tzurl = "TZURL" tzurlparam ":" uri CRLF 4927 tzurlparam = *(";" xparam) 4929 Example: The following is an example of this property: 4931 TZURL:http://timezones.r.us.net/tz/US-California-Los_Angeles 4933 4.8.4 Relationship Component Properties 4935 The following properties specify relationship information in calendar 4936 components. 4938 4.8.4.1 Attendee 4940 Property Name: ATTENDEE 4942 Purpose: The property defines an "Attendee" within a calendar 4943 component. 4945 Value Type: CAL-ADDRESS 4947 Property Parameters: Non-standard, language, calendar user type, 4948 group or list membership, participation role, participation status, 4949 RSVP expectation, delegatee, delegator, sent by, common name or 4950 directory entry reference property parameters can be specified on 4951 this property. 4953 Conformance: This property MUST be specified in an iCalendar object 4954 that specifies a group scheduled calendar entity. This property MUST 4955 NOT be specified in an iCalendar object when publishing the calendar 4956 information (e.g., NOT in an iCalendar object that specifies the 4957 publication of a calendar user's busy time, event, to-do or journal). 4958 This property is not specified in an iCalendar object that specifies 4959 only a time zone definition or that defines calendar entities that 4960 are not group scheduled entities, but are entities only on a single 4961 user's calendar. 4963 Description: The property MUST only be specified within calendar 4964 components to specify participants, non-participants and the chair of 4965 a group scheduled calendar entity. The property is specified within 4967 Dawson/Stenerson 92 Expires February 1999 4968 an "EMAIL" category of the "VALARM" calendar component to specify an 4969 email address that is to receive the email type of iCalendar alarm. 4971 The property parameter CN is for the common or displayable name 4972 associated with the calendar address; ROLE, for the intended role 4973 that the attendee will have in the calendar component; PARTSTAT, for 4974 the status of the attendee�s participation; RSVP, for indicating 4975 whether the favor of a reply is requested; CUTYPE, to indicate the 4976 type of calendar user; MEMBER, to indicate the groups that the 4977 attendee belongs to; DELEGATED-TO, to indicate the calendar users 4978 that the original request was delegated to; and DELEGATED-FROM, to 4979 indicate whom the request was delegated from; SENT-BY, to indicate 4980 whom is acting on behalf of the ATTENDEE; and DIR, to indicate the 4981 URI that points to the directory information corresponding to the 4982 attendee. These property parameters can be specified on an "ATTENDEE" 4983 property in either a "VEVENT", "VTODO" or "VJOURNAL" calendar 4984 component. They MUST not be specified in an "ATTENDEE" property in a 4985 "VFREEBUSY" or "VALARM" calendar component. If the LANGUAGE property 4986 parameter is specified, the identified language applies to the CN 4987 parameter. 4989 A recipient delegated a request MUST inherit the RSVP and ROLE values 4990 from the attendee that delegated the request to them. 4992 Multiple attendees can be specified by including multiple "ATTENDEE" 4993 properties within the calendar component. 4995 Format Definition: The property is defined by the following notation: 4997 attendee = "ATTENDEE" attparam ":" cal-address CRLF 4999 attparam = *( 5001 ; the following are optional, 5002 ; but MUST NOT occur more than once 5004 (";" cutypeparam) / (";"memberparam) / 5005 (";" roleparam) / (";" partstatparam) / 5006 (";" rsvpparam) / (";" deltoparam) / 5007 (";" delfromparam) / (";" sentbyparam) / 5008 (";"cnparam) / (";" dirparam) / 5009 (";" languageparam) / 5011 ; the following is optional, 5012 ; and MAY occur more than once 5014 (";" xparam) 5016 ) 5018 Example: The following are examples of this property�s use for a to- 5019 do: 5021 Dawson/Stenerson 93 Expires February 1999 5022 ORGANIZER:MAILTO:jsmith@host1.com 5023 ATTENDEE;MEMBER="MAILTO:DEV-GROUP@host2.com": 5024 MAILTO:joecool@host2.com 5025 ATTENDEE;DELEGATED-FROM="MAILTO:immud@host3.com": 5026 MAILTO:ildoit@host1.com 5028 The following is an example of this property used for specifying 5029 multiple attendees to an event: 5031 ORGANIZER:MAILTO:jsmith@host1.com 5032 ATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=TENTATIVE;CN=Henry Cabot 5033 :MAILTO:hcabot@host2.com 5034 ATTENDEE;ROLE=REQ-PARTICIPANT;DELEGATED-FROM="MAILTO:bob@host.com" 5035 ;PARTSTAT=ACCEPTED;CN=Jane Doe:MAILTO:jdoe@host1.com 5037 The following is an example of this property with a URI to the 5038 directory information associated with the attendee: 5040 ATTENDEE;CN=John Smith;DIR="ldap://host.com:6666/o=eDABC% 5041 20Industries,c=3DUS??(cn=3DBJim%20Dolittle)":MAILTO:jimdo@ 5042 host1.com 5044 The following is an example of this property with "delegatee" and 5045 "delegator" information for an event: 5047 ORGANIZER;CN=John Smith:MAILTO:jsmith@host.com 5048 ATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=TENTATIVE;DELEGATED-FROM= 5049 "MAILTO:iamboss@host2.com";CN=Henry Cabot:MAILTO:hcabot@ 5050 host2.com 5051 ATTENDEE;ROLE=NON-PARTICIPANT;PARTSTAT=DELEGATED;DELEGATED-TO= 5052 "MAILTO:hcabot@host2.com";CN=The Big Cheese:MAILTO:iamboss 5053 @host2.com 5054 ATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=ACCEPTED;CN=Jane Doe 5055 :MAILTO:jdoe@host1.com 5057 Example: The following is an example of this property�s use when 5058 another calendar user is acting on behalf of the "Attendee": 5060 ATTENDEE;SENT-BY=MAILTO:jan_doe@host1.com;CN=John Smith:MAILTO: 5061 jsmith@host1.com 5063 4.8.4.2 Contact 5065 Property Name: CONTACT 5067 Purpose: The property is used to represent contact information or 5068 alternately a reference to contact information associated with the 5069 calendar component. 5071 Value Type: TEXT 5073 Property Parameters: Non-standard, alternate text representation and 5074 language property parameters can be specified on this property. 5076 Dawson/Stenerson 94 Expires February 1999 5077 Conformance: The property can be specified in a "VEVENT", "VTODO", 5078 "VJOURNAL" or "VFREEBUSY" calendar component. 5080 Description: The property value consists of textual contact 5081 information. An alternative representation for the property value can 5082 also be specified that refers to a URI pointing to an alternate form, 5083 such as a vCard, for the contact information. 5085 Format Definition: The property is defined by the following notation: 5087 contact = "CONTACT" contparam ":" text CRLF 5089 contparam = *( 5091 ; the following are optional, 5092 ; but MUST NOT occur more than once 5094 (";" altrepparam) / (";" languageparam) / 5096 ; the following is optional, 5097 ; and MAY occur more than once 5099 (";" xparam) 5101 ) 5103 Example: The following is an example of this property referencing 5104 textual contact information: 5106 CONTACT:Jim Dolittle\, ABC Industries\, +1-919-555-1234 5108 The following is an example of this property with an alternate 5109 representation of a LDAP URI to a directory entry containing the 5110 contact information: 5112 CONTACT;ALTREP="ldap://host.com:6666/o=3DABC%20Industries\, 5113 c=3DUS??(cn=3DBJim%20Dolittle)":Jim Dolittle\, ABC Industries\, 5114 +1-919-555-1234 5116 The following is an example of this property with an alternate 5117 representation of a MIME body part containing the contact 5118 information, such as a vCard embedded in a [MIME-DIR] content-type: 5120 CONTACT;ALTREP="CID=":Jim 5121 Dolittle\, ABC Industries\, +1-919-555-1234 5123 The following is an example of this property referencing a network 5124 resource, such as a vCard object containing the contact information: 5126 CONTACT;ALTREP="http://host.com/pdi/jdoe.vcf":Jim 5127 Dolittle\, ABC Industries\, +1-919-555-1234 5129 Dawson/Stenerson 95 Expires February 1999 5130 4.8.4.3 Organizer 5132 Property Name: ORGANIZER 5134 Purpose: The property defines the organizer for a calendar component. 5136 Value Type: CAL-ADDRESS 5138 Property Parameters: Non-standard, language, common name, directory 5139 entry reference, sent by property parameters can be specified on this 5140 property. 5142 Conformance: This property MUST be specified in an iCalendar object 5143 that specifies a group scheduled calendar entity. This property MUST 5144 be specified in an iCalendar object that specifies the publication of 5145 a calendar user's busy time. This property MUST NOT be specified in 5146 an iCalendar object that specifies only a time zone definition or 5147 that defines calendar entities that are not group scheduled entities, 5148 but are entities only on a single user's calendar. 5150 Description: The property is specified within the "VEVENT", "VTODO", 5151 "VJOURNAL calendar components to specify the organizer of a group 5152 scheduled calendar entity. The property is specified within the 5153 "VFREEBUSY" calendar component to specify the calendar user 5154 requesting the free or busy time. When publishing a "VFREEBUSY" 5155 calendar component, the property is used to specify the calendar that 5156 the published busy time came from. 5158 The property has the property parameters CN, for specifying the 5159 common or display name associated with the "Organizer", DIR, for 5160 specifying a pointer to the directory information associated with the 5161 "Organizer", SENT-BY, for specifying another calendar user that is 5162 acting on behalf of the "Organizer". The non-standard parameters may 5163 also be specified on this property. If the LANGUAGE property 5164 parameter is specified, the identified language applies to the CN 5165 parameter value. 5167 Format Definition: The property is defined by the following notation: 5169 organizer = "ORGANIZER" orgparam ":" 5170 cal-address CRLF 5172 orgparam = *( 5174 ; the following are optional, 5175 ; but MUST NOT occur more than once 5177 (";" cnparam) / (";" dirparam) / (";" sentbyparam) / 5178 (";" languageparam) / 5180 ; the following is optional, 5181 ; and MAY occur more than once 5183 Dawson/Stenerson 96 Expires February 1999 5184 (";" xparam) 5186 ) 5188 Example: The following is an example of this property: 5190 ORGANIZER;CN=John Smith:MAILTO:jsmith@host1.com 5192 The following is an example of this property with a pointer to the 5193 directory information associated with the organizer: 5195 ORGANIZER;CN=JohnSmith;DIR="ldap://host.com:6666/o=3DDC%20Associ 5196 ates,c=3DUS??(cn=3DJohn%20Smith)":MAILTO:jsmith@host1.com 5198 The following is an example of this property used by another calendar 5199 user who is acting on behalf of the organizer, with responses 5200 intended to be sent back to the organizer, not the other calendar 5201 user: 5203 ORGANIZER;SENT-BY="MAILTO:jane_doe@host.com": 5204 MAILTO:jsmith@host1.com 5206 4.8.4.4 Recurrence ID 5208 Property Name: RECURRENCE-ID 5210 Purpose: This property is used in conjunction with the "UID" and 5211 "SEQUENCE" property to identify a specific instance of a recurring 5212 "VEVENT", "VTODO" or "VJOURNAL" calendar component. The property 5213 value is the effective value of the "DTSTART" property of the 5214 recurrence instance. 5216 Value Type: The default value type for this property is DATE-TIME. 5217 The time format can be any of the valid forms defined for a DATE-TIME 5218 value type. See DATE-TIME value type definition for specific 5219 interpretations of the various forms. The value type can be set to 5220 DATE. 5222 Property Parameters: Non-standard property, value data type, time 5223 zone identifier and recurrence identifier range parameters can be 5224 specified on this property. 5226 Conformance: This property can be specified in an iCalendar object 5227 containing a recurring calendar component. 5229 Description: The full range of calendar components specified by a 5230 recurrence set is referenced by referring to just the "UID" property 5231 value corresponding to the calendar component. The "RECURRENCE-ID" 5232 property allows the reference to an individual instance within the 5233 recurrence set. 5235 If the value of the "DTSTART" property is a DATE type value, then the 5236 value MUST be the calendar date for the recurrence instance. 5238 Dawson/Stenerson 97 Expires February 1999 5239 The date/time value is set to the time when the original recurrence 5240 instance would occur; meaning that if the intent is to change a 5241 Friday meeting to Thursday, the date/time is still set to the 5242 original Friday meeting. 5244 The "RECURRENCE-ID" property is used in conjunction with the "UID" 5245 and "SEQUENCE" property to identify a particular instance of a 5246 recurring event, to-do or journal. For a given pair of "UID" and 5247 "SEQUENCE" property values, the "RECURRENCE-ID" value for a 5248 recurrence instance is fixed. When the definition of the recurrence 5249 set for a calendar component changes, and hence the "SEQUENCE" 5250 property value changes, the "RECURRENCE-ID" for a given recurrence 5251 instance might also change.The "RANGE" parameter is used to specify 5252 the effective range of recurrence instances from the instance 5253 specified by the "RECURRENCE-ID" property value. The default value 5254 for the range parameter is the single recurrence instance only. The 5255 value can also be "THISANDPRIOR" to indicate a range defined by the 5256 given recurrence instance and all prior instances or the value can be 5257 "THISANDFUTURE" to indicate a range defined by the given recurrence 5258 instance and all subsequent instances. 5260 Format Definition: The property is defined by the following notation: 5262 recurid = "RECURRENCE-ID" ridparam ":" ridval CRLF 5264 ridparam = *( 5266 ; the following are optional, 5267 ; but MUST NOT occur more than once 5269 (";" "VALUE" "=" ("DATE-TIME" / "DATE)) / 5270 (";" tzidparam) / (";" rangeparam) / 5272 ; the following is optional, 5273 ; and MAY occur more than once 5275 (";" xparam) 5277 ) 5279 ridval = date-time / date 5280 ;Value MUST match value type 5282 Example: The following are examples of this property: 5284 RECURRENCE-ID;VALUE=DATE:19960401 5286 RECURRENCE-ID;RANGE=THISANDFUTURE:19960120T120000Z 5288 4.8.4.5 Related To 5290 Property Name: RELATED-TO 5292 Dawson/Stenerson 98 Expires February 1999 5293 Purpose: The property is used to represent a relationship or 5294 reference between one calendar component and another. 5296 Value Type: TEXT 5298 Property Parameters: Non-standard and relationship type property 5299 parameters can be specified on this property. 5301 Conformance: The property can be specified once in the "VEVENT", 5302 "VTODO" or "VJOURNAL" calendar components. 5304 Description: The property value consists of the persistent, globally 5305 unique identifier of another calendar component. This value would be 5306 represented in a calendar component by the "UID" property. 5308 By default, the property value points to another calendar component 5309 that has a PARENT relationship to the referencing object. The 5310 "RELTYPE" property parameter is used to either explicitly state the 5311 default PARENT relationship type to the referenced calendar component 5312 or to override the default PARENT relationship type and specify 5313 either a CHILD or SIBLING relationship. The PARENT relationship 5314 indicates that the calendar component is a subordinate of the 5315 referenced calendar component. The CHILD relationship indicates that 5316 the calendar component is a superior of the referenced calendar 5317 component. The SIBLING relationship indicates that the calendar 5318 component is a peer of the referenced calendar component. 5320 Changes to a calendar component referenced by this property can have 5321 an implicit impact on the related calendar component. For example, if 5322 a group event changes its start or end date or time, then the 5323 related, dependent events will need to have their start and end dates 5324 changed in a corresponding way. Similarly, if a PARENT calendar 5325 component is canceled or deleted, then there is an implied impact to 5326 the related CHILD calendar components. This property is intended only 5327 to provide information on the relationship of calendar components. It 5328 is up to the target calendar system to maintain any property 5329 implications of this relationship. 5331 Format Definition: The property is defined by the following notation: 5333 related = "RELATED-TO" [relparam] ":" text CRLF 5335 relparam = *( 5337 ; the following is optional, 5338 ; but MUST NOT occur more than once 5340 (";" reltypeparam) / 5342 ; the following is optional, 5343 ; and MAY occur more than once 5345 (";" xparm) 5347 Dawson/Stenerson 99 Expires February 1999 5348 ) 5350 The following is an example of this property: 5352 RELATED-TO: 5354 RELATED-TO:<19960401-080045-4000F192713-0052@host1.com> 5356 4.8.4.6 Uniform Resource Locator 5358 Property Name: URL 5360 Purpose: This property defines a Uniform Resource Locator (URL) 5361 associated with the iCalendar object. 5363 Value Type: URI 5365 Property Parameters: Non-standard property parameters can be 5366 specified on this property. 5368 Conformance: This property can be specified once in the "VEVENT", 5369 "VTODO", "VJOURNAL" or "VFREEBUSY" calendar components. 5371 Description: This property may be used in a calendar component to 5372 convey a location where a more dynamic rendition of the calendar 5373 information associated with the calendar component can be found. This 5374 memo does not attempt to standardize the form of the URI, nor the 5375 format of the resource pointed to by the property value. If the URL 5376 property and Content-Location MIME header are both specified, they 5377 MUST point to the same resource. 5379 Format Definition: The property is defined by the following notation: 5381 url = "URL" urlparam ":" uri CRLF 5383 urlparam = *(";" xparam) 5385 Example: The following is an example of this property: 5387 URL:http://abc.com/pub/calendars/jsmith/mytime.ics 5389 4.8.4.7 Unique Identifier 5391 Property Name: UID 5393 Purpose: This property defines the persistent, globally unique 5394 identifier for the calendar component. 5396 Value Type: TEXT 5398 Property Parameters: Non-standard property parameters can be 5399 specified on this property. 5401 Dawson/Stenerson 100 Expires February 1999 5402 Conformance: The property MUST be specified in the "VEVENT", "VTODO", 5403 "VJOURNAL" or "VFREEBUSY" calendar components. 5405 Description: The UID itself MUST be a globally unique identifier. The 5406 generator of the identifier MUST guarantee that the identifier is 5407 unique. There are several algorithms that can be used to accomplish 5408 this. The identifier is RECOMMENDED to be the identical syntax to the 5409 [RFC 822] addr-spec. A good method to assure uniqueness is to put the 5410 domain name or a domain literal IP address of the host on which the 5411 identifier was created on the right hand side of the "@", and on the 5412 left hand side, put a combination of the current calendar date and 5413 time of day (i.e., formatted in as a DATE-TIME value) along with some 5414 other currently unique (perhaps sequential) identifier available on 5415 the system (for example, a process id number). Using a date/time 5416 value on the left hand side and a domain name or domain literal on 5417 the right hand side makes it possible to guarantee uniqueness since 5418 no two hosts should be using the same domain name or IP address at 5419 the same time. Though other algorithms will work, it is RECOMMENDED 5420 that the right hand side contain some domain identifier (either of 5421 the host itself or otherwise) such that the generator of the message 5422 identifier can guarantee the uniqueness of the left hand side within 5423 the scope of that domain. 5425 This is the method for correlating scheduling messages with the 5426 referenced "VEVENT", "VTODO", or "VJOURNAL" calendar component. 5428 The full range of calendar components specified by a recurrence set 5429 is referenced by referring to just the "UID" property value 5430 corresponding to the calendar component. The "RECURRENCE-ID" property 5431 allows the reference to an individual instance within the recurrence 5432 set. 5434 This property is an important method for group scheduling 5435 applications to match requests with later replies, modifications or 5436 deletion requests. Calendaring and scheduling applications MUST 5437 generate this property in "VEVENT", "VTODO" and "VJOURNAL" calendar 5438 components to assure interoperability with other group scheduling 5439 applications. This identifier is created by the calendar system that 5440 generates an iCalendar object. 5442 Implementations MUST be able to receive and persist values of at 5443 least 255 characters for this property. 5445 Format Definition: The property is defined by the following notation: 5447 uid = "UID" uidparam ":" text CRLF 5449 uidparam = *(";" xparam) 5451 Example: The following is an example of this property: 5453 UID:19960401T080045Z-4000F192713-0052@host1.com 5455 Dawson/Stenerson 101 Expires February 1999 5456 4.8.5 Recurrence Component Properties 5458 The following properties specify recurrence information in calendar 5459 components. 5461 4.8.5.1 Exception Date/Times 5463 Property Name: EXDATE 5465 Purpose: This property defines the list of date/time exceptions for a 5466 recurring calendar component. 5468 Value Type: The default value type for this property is DATE-TIME. 5469 The value type can be set to DATE. 5471 Property Parameters: Non-standard, value data type and time zone 5472 identifier property parameters can be specified on this property. 5474 Conformance: This property can be specified in an iCalendar object 5475 that includes a recurring calendar component. 5477 Description: The exception dates, if specified, are used in computing 5478 the recurrence set. The recurrence set is the complete set of 5479 recurrence instances for a calendar component. The recurrence set is 5480 generated by considering the initial "DTSTART" property along with 5481 the "RRULE", "RDATE", "EXDATE" and "EXRULE" properties contained 5482 within the iCalendar object. The "DTSTART" property defines the first 5483 instance in the recurrence set. Multiple instances of the "RRULE" and 5484 "EXRULE" properties can also be specified to define more 5485 sophisticated recurrence sets. The final recurrence set is generated 5486 by gathering all of the start date-times generated by any of the 5487 specified "RRULE" and "RDATE" properties, and then excluding any 5488 start date and times which fall within the union of start date and 5489 times generated by any specified "EXRULE" and "EXDATE" properties. 5490 This implies that start date and times within exclusion related 5491 properties (i.e., "EXDATE" and "EXRULE") take precedence over those 5492 specified by inclusion properties (i.e., "RDATE" and "RRULE"). Where 5493 duplicate instances are generated by the "RRULE" and "RDATE" 5494 properties, only one recurrence is considered. Duplicate instances 5495 are ignored. 5497 The "EXDATE" property can be used to exclude the value specified in 5498 "DTSTART". However, in such cases the original "DTSTART" date MUST 5499 still be maintained by the calendaring and scheduling system because 5500 the original "DTSTART" value has inherent usage dependencies by other 5501 properties such as the "RECURRENCE-ID". 5503 Format Definition: The property is defined by the following notation: 5505 exdate = "EXDATE" exdtparam ":" exdtval *("," exdtval) CRLF 5507 exdtparam = *( 5509 Dawson/Stenerson 102 Expires February 1999 5510 ; the following are optional, 5511 ; but MUST NOT occur more than once 5513 (";" "VALUE" "=" ("DATE-TIME" / "DATE")) / 5514 (";" tzidparam) / 5516 ; the following is optional, 5517 ; and MAY occur more than once 5519 (";" xparam) 5521 ) 5523 exdtval = date-time / date 5524 ;Value MUST match value type 5526 Example: The following is an example of this property: 5528 EXDATE:19960402T010000Z,19960403T010000Z,19960404T010000Z 5530 4.8.5.2 Exception Rule 5532 Property Name: EXRULE 5534 Purpose: This property defines a rule or repeating pattern for an 5535 exception to a recurrence set. 5537 Value Type: RECUR 5539 Property Parameters: Non-standard property parameters can be 5540 specified on this property. 5542 Conformance: This property can be specified in "VEVENT", "VTODO" or 5543 "VJOURNAL" calendar components. 5545 Description: The exception rule, if specified, is used in computing 5546 the recurrence set. The recurrence set is the complete set of 5547 recurrence instances for a calendar component. The recurrence set is 5548 generated by considering the initial "DTSTART" property along with 5549 the "RRULE", "RDATE", "EXDATE" and "EXRULE" properties contained 5550 within the iCalendar object. The "DTSTART" defines the first instance 5551 in the recurrence set. Multiple instances of the "RRULE" and "EXRULE" 5552 properties can also be specified to define more sophisticated 5553 recurrence sets. The final recurrence set is generated by gathering 5554 all of the start date-times generated by any of the specified "RRULE" 5555 and "RDATE" properties, and excluding any start date and times which 5556 fall within the union of start date and times generated by any 5557 specified "EXRULE" and "EXDATE" properties. This implies that start 5558 date and times within exclusion related properties (i.e., "EXDATE" 5559 and "EXRULE") take precedence over those specified by inclusion 5560 properties (i.e., "RDATE" and "RRULE"). Where duplicate instances are 5561 generated by the "RRULE" and "RDATE" properties, only one recurrence 5562 is considered. Duplicate instances are ignored. 5564 Dawson/Stenerson 103 Expires February 1999 5565 The "EXRULE" property can be used to exclude the value specified in 5566 "DTSTART". However, in such cases the original "DTSTART" date MUST 5567 still be maintained by the calendaring and scheduling system because 5568 the original "DTSTART" value has inherent usage dependencies by other 5569 properties such as the "RECURRENCE-ID". 5571 Format Definition: The property is defined by the following notation: 5573 exrule = "EXRULE" exrparam ":" recur CRLF 5575 exrparam = *(";" xparam) 5577 Example: The following are examples of this property. Except every 5578 other week, on Tuesday and Thursday for 4 occurrences: 5580 EXRULE:FREQ=WEEKLY;COUNT=4;INTERVAL=2;BYDAY=TU,TH 5582 Except daily for 10 occurrences: 5584 EXRULE:FREQ=DAILY;COUNT=10 5586 Except yearly in June and July for 8 occurrences: 5588 EXRULE:FREQ=YEARLY;COUNT=8;BYMONTH=6,7 5590 4.8.5.3 Recurrence Date/Times 5592 Property Name: RDATE 5594 Purpose: This property defines the list of date/times for a 5595 recurrence set. 5597 Value Type: The default value type for this property is DATE-TIME. 5598 The value type can be set to DATE or PERIOD. 5600 Property Parameters: Non-standard, value data type and time zone 5601 identifier property parameters can be specified on this property. 5603 Conformance: The property can be specified in "VEVENT", "VTODO", 5604 "VJOURNAL" or "VTIMEZONE" calendar components. 5606 Description: This property can appear along with the "RRULE" property 5607 to define an aggregate set of repeating occurrences. When they both 5608 appear in an iCalendar object, the recurring events are defined by 5609 the union of occurrences defined by both the "RDATE" and "RRULE". 5611 The recurrence dates, if specified, are used in computing the 5612 recurrence set. The recurrence set is the complete set of recurrence 5613 instances for a calendar component. The recurrence set is generated 5614 by considering the initial "DTSTART" property along with the "RRULE", 5615 "RDATE", "EXDATE" and "EXRULE" properties contained within the 5616 iCalendar object. The "DTSTART" property defines the first instance 5617 in the recurrence set. Multiple instances of the "RRULE" and "EXRULE" 5619 Dawson/Stenerson 104 Expires February 1999 5620 properties can also be specified to define more sophisticated 5621 recurrence sets. The final recurrence set is generated by gathering 5622 all of the start date/times generated by any of the specified "RRULE" 5623 and "RDATE" properties, and excluding any start date/times which fall 5624 within the union of start date/times generated by any specified 5625 "EXRULE" and "EXDATE" properties. This implies that start date/times 5626 within exclusion related properties (i.e., "EXDATE" and "EXRULE") 5627 take precedence over those specified by inclusion properties (i.e., 5628 "RDATE" and "RRULE"). Where duplicate instances are generated by the 5629 "RRULE" and "RDATE" properties, only one recurrence is considered. 5630 Duplicate instances are ignored. 5632 Format Definition: The property is defined by the following notation: 5634 rdate = "RDATE" rdtparam ":" rdtval *("," rdtval) CRLF 5636 rdtparam = *( 5638 ; the following are optional, 5639 ; but MUST NOT occur more than once 5641 (";" "VALUE" "=" ("DATE-TIME" / "DATE" / "PERIOD")) / 5642 (";" tzidparam) / 5644 ; the following is optional, 5645 ; and MAY occur more than once 5647 (";" xparam) 5649 ) 5651 rdtval = date-time / date / period 5652 ;Value MUST match value type 5654 Example: The following are examples of this property: 5656 RDATE:19970714T123000Z 5658 RDATE;TZID=US-EASTERN:19970714T083000 5660 RDATE;VALUE=PERIOD:19960403T020000Z/19960403T040000Z, 5661 19960404T010000Z/PT3H 5663 RDATE;VALUE=DATE:19970101,19970120,19970217,19970421 5664 19970526,19970704,19970901,19971014,19971128,19971129,19971225 5666 4.8.5.4 Recurrence Rule 5668 Property Name: RRULE 5670 Purpose: This property defines a rule or repeating pattern for 5671 recurring events, to-dos, or time zone definitions. 5673 Dawson/Stenerson 105 Expires February 1999 5674 Value Type: RECUR 5676 Property Parameters: Non-standard property parameters can be 5677 specified on this property. 5679 Conformance: This property can be specified one or more times in 5680 recurring "VEVENT", "VTODO" and "VJOURNAL" calendar components. It 5681 can also be specified once in each STANDARD or DAYLIGHT sub-component 5682 of the "VTIMEZONE" calendar component. 5684 Description: The recurrence rule, if specified, is used in computing 5685 the recurrence set. The recurrence set is the complete set of 5686 recurrence instances for a calendar component. The recurrence set is 5687 generated by considering the initial "DTSTART" property along with 5688 the "RRULE", "RDATE", "EXDATE" and "EXRULE" properties contained 5689 within the iCalendar object. The "DTSTART" property defines the first 5690 instance in the recurrence set. Multiple instances of the "RRULE" and 5691 "EXRULE" properties can also be specified to define more 5692 sophisticated recurrence sets. The final recurrence set is generated 5693 by gathering all of the start date/times generated by any of the 5694 specified "RRULE" and "RDATE" properties, and excluding any start 5695 date/times which fall within the union of start date/times generated 5696 by any specified "EXRULE" and "EXDATE" properties. This implies that 5697 start date/times within exclusion related properties (i.e., "EXDATE" 5698 and "EXRULE") take precedence over those specified by inclusion 5699 properties (i.e., "RDATE" and "RRULE"). Where duplicate instances are 5700 generated by the "RRULE" and "RDATE" properties, only one recurrence 5701 is considered. Duplicate instances are ignored. 5703 The "DTSTART" and "DTEND" property pair or "DTSTART" and "DURATION" 5704 property pair, specified within the iCalendar object defines the 5705 first instance of the recurrence. When used with a recurrence rule, 5706 the "DTSTART" and "DTEND" properties MUST be specified in local time 5707 and the appropriate set of "VTIMEZONE" calendar components MUST be 5708 included. For detail on the usage of the "VTIMEZONE" calendar 5709 component, see the "VTIMEZONE" calendar component definition. 5711 Any duration associated with the iCalendar object applies to all 5712 members of the generated recurrence set. Any modified duration for 5713 specific recurrences MUST be explicitly specified using the "RDATE" 5714 property. 5716 Format Definition: This property is defined by the following 5717 notation: 5719 rrule = "RRULE" rrulparam ":" recur CRLF 5721 rrulparam = *(";" xparam) 5723 Example: All examples assume the Eastern United States time zone. 5725 Daily for 10 occurrences: 5727 DTSTART;TZID=US-Eastern:19970902T090000 5729 Dawson/Stenerson 106 Expires February 1999 5730 RRULE:FREQ=DAILY;COUNT=10 5732 ==> (1997 9:00 AM EDT)September 2-11 5734 Daily until December 24, 1997: 5736 DTSTART;TZID=US-Eastern:19970902T090000 5737 RRULE:FREQ=DAILY;UNTIL=19971224T000000Z 5739 ==> (1997 9:00 AM EDT)September 2-30;October 1-25 5740 (1997 9:00 AM EST)October 26-31;November 1-30;December 1-23 5742 Every other day - forever: 5744 DTSTART;TZID=US-Eastern:19970902T090000 5745 RRULE:FREQ=DAILY;INTERVAL=2 5746 ==> (1997 9:00 AM EDT)September2,4,6,8...24,26,28,30; 5747 October 2,4,6...20,22,24 5748 (1997 9:00 AM EST)October 26,28,30;November 1,3,5,7...25,27,29; 5749 Dec 1,3,... 5751 Every 10 days, 5 occurrences: 5753 DTSTART;TZID=US-Eastern:19970902T090000 5754 RRULE:FREQ=DAILY;INTERVAL=10;COUNT=5 5756 ==> (1997 9:00 AM EDT)September 2,12,22;October 2,12 5758 Everyday in January, for 3 years: 5760 DTSTART;TZID=US-Eastern:19980101T090000 5761 RRULE:FREQ=YEARLY;UNTIL=20000131T090000Z; 5762 BYMONTH=1;BYDAY=SU,MO,TU,WE,TH,FR,SA 5763 or 5764 RRULE:FREQ=DAILY;UNTIL=20000131T090000Z;BYMONTH=1 5766 ==> (1998 9:00 AM EDT)January 1-31 5767 (1999 9:00 AM EDT)January 1-31 5768 (2000 9:00 AM EDT)January 1-31 5770 Weekly for 10 occurrences 5772 DTSTART;TZID=US-Eastern:19970902T090000 5773 RRULE:FREQ=WEEKLY;COUNT=10 5775 ==> (1997 9:00 AM EDT)September 2,9,16,23,30;October 7,14,21 5776 (1997 9:00 AM EST)October 28;November 4 5778 Weekly until December 24, 1997 5780 DTSTART;TZID=US-Eastern:19970902T090000 5781 RRULE:FREQ=WEEKLY;UNTIL=19971224T000000Z 5783 ==> (1997 9:00 AM EDT)September 2,9,16,23,30;October 7,14,21 5785 Dawson/Stenerson 107 Expires February 1999 5786 (1997 9:00 AM EST)October 28;November 4,11,18,25; 5787 December 2,9,16,23 5789 Every other week - forever: 5791 DTSTART;TZID=US-Eastern:19970902T090000 5792 RRULE:FREQ=WEEKLY;INTERVAL=2;WKST=SU 5794 ==> (1997 9:00 AM EDT)September 2,16,30;October 14 5795 (1997 9:00 AM EST)October 28;November 11,25;December 9,23 5796 (1998 9:00 AM EST)January 6,20;February 5797 ... 5799 Weekly on Tuesday and Thursday for 5 weeks: 5801 DTSTART;TZID=US-Eastern:19970902T090000 5802 RRULE:FREQ=WEEKLY;UNTIL=19971007T000000Z;WKST=SU;BYDAY=TU,TH 5803 or 5804 RRULE:FREQ=WEEKLY;COUNT=10;WKST=SU;BYDAY=TU,TH 5806 ==> (1997 9:00 AM EDT)September 2,4,9,11,16,18,23,25,30;October 2 5808 Every other week on Monday, Wednesday and Friday until December 24, 5809 1997, but starting on Tuesday, September 2, 1997: 5811 DTSTART;TZID=US-Eastern:19970902T090000 5812 RRULE:FREQ=WEEKLY;INTERVAL=2;UNTIL=19971224T000000Z;WKST=SU; 5813 BYDAY=MO,WE,FR 5814 ==> (1997 9:00 AM EDT)September 2,3,5,15,17,19,29;October 5815 1,3,13,15,17 5816 (1997 9:00 AM EST)October 27,29,31;November 10,12,14,24,26,28; 5817 December 8,10,12,22 5819 Every other week on Tuesday and Thursday, for 8 occurrences: 5821 DTSTART;TZID=US-Eastern:19970902T090000 5822 RRULE:FREQ=WEEKLY;INTERVAL=2;COUNT=8;WKST=SU;BYDAY=TU,TH 5824 ==> (1997 9:00 AM EDT)September 2,4,16,18,30;October 2,14,16 5826 Monthly on the 1st Friday for ten occurrences: 5828 DTSTART;TZID=US-Eastern:19970905T090000 5829 RRULE:FREQ=MONTHLY;COUNT=10;BYDAY=1FR 5831 ==> (1997 9:00 AM EDT)September 5;October 3 5832 (1997 9:00 AM EST)November 7;Dec 5 5833 (1998 9:00 AM EST)January 2;February 6;March 6;April 3 5834 (1998 9:00 AM EDT)May 1;June 5 5836 Monthly on the 1st Friday until December 24, 1997: 5838 DTSTART;TZID=US-Eastern:19970905T090000 5840 Dawson/Stenerson 108 Expires February 1999 5841 RRULE:FREQ=MONTHLY;UNTIL=19971224T000000Z;BYDAY=1FR 5843 ==> (1997 9:00 AM EDT)September 5;October 3 5844 (1997 9:00 AM EST)November 7;December 5 5846 Every other month on the 1st and last Sunday of the month for 10 5847 occurrences: 5849 DTSTART;TZID=US-Eastern:19970907T090000 5850 RRULE:FREQ=MONTHLY;INTERVAL=2;COUNT=10;BYDAY=1SU,-1SU 5852 ==> (1997 9:00 AM EDT)September 7,28 5853 (1997 9:00 AM EST)November 2,30 5854 (1998 9:00 AM EST)January 4,25;March 1,29 5855 (1998 9:00 AM EDT)May 3,31 5857 Monthly on the second to last Monday of the month for 6 months: 5859 DTSTART;TZID=US-Eastern:19970922T090000 5860 RRULE:FREQ=MONTHLY;COUNT=6;BYDAY=-2MO 5862 ==> (1997 9:00 AM EDT)September 22;October 20 5863 (1997 9:00 AM EST)November 17;December 22 5864 (1998 9:00 AM EST)January 19;February 16 5866 Monthly on the third to the last day of the month, forever: 5868 DTSTART;TZID=US-Eastern:19970928T090000 5869 RRULE:FREQ=MONTHLY;BYMONTHDAY=-3 5871 ==> (1997 9:00 AM EDT)September 28 5872 (1997 9:00 AM EST)October 29;November 28;December 29 5873 (1998 9:00 AM EST)January 29;February 26 5874 ... 5876 Monthly on the 2nd and 15th of the month for 10 occurrences: 5878 DTSTART;TZID=US-Eastern:19970902T090000 5879 RRULE:FREQ=MONTHLY;COUNT=10;BYMONTHDAY=2,15 5881 ==> (1997 9:00 AM EDT)September 2,15;October 2,15 5882 (1997 9:00 AM EST)November 2,15;December 2,15 5883 (1998 9:00 AM EST)January 2,15 5885 Monthly on the first and last day of the month for 10 occurrences: 5887 DTSTART;TZID=US-Eastern:19970930T090000 5888 RRULE:FREQ=MONTHLY;COUNT=10;BYMONTHDAY=1,-1 5890 ==> (1997 9:00 AM EDT)September 30;October 1 5891 (1997 9:00 AM EST)October 31;November 1,30;December 1,31 5892 (1998 9:00 AM EST)January 1,31;February 1 5894 Dawson/Stenerson 109 Expires February 1999 5895 Every 18 months on the 10th thru 15th of the month for 10 5896 occurrences: 5898 DTSTART;TZID=US-Eastern:19970910T090000 5899 RRULE:FREQ=MONTHLY;INTERVAL=18;COUNT=10;BYMONTHDAY=10,11,12,13,14, 5900 15 5902 ==> (1997 9:00 AM EDT)September 10,11,12,13,14,15 5903 (1999 9:00 AM EST)March 10,11,12,13 5905 Every Tuesday, every other month: 5907 DTSTART;TZID=US-Eastern:19970902T090000 5908 RRULE:FREQ=MONTHLY;INTERVAL=2;BYDAY=TU 5910 ==> (1997 9:00 AM EDT)September 2,9,16,23,30 5911 (1997 9:00 AM EST)November 4,11,18,25 5912 (1998 9:00 AM EST)January 6,13,20,27;March 3,10,17,24,31 5913 ... 5915 Yearly in June and July for 10 occurrences: 5917 DTSTART;TZID=US-Eastern:19970610T090000 5918 RRULE:FREQ=YEARLY;COUNT=10;BYMONTH=6,7 5920 ==> (1997 9:00 AM EDT)June 10;July 10 5921 (1998 9:00 AM EDT)June 10;July 10 5922 (1999 9:00 AM EDT)June 10;July 10 5923 (2000 9:00 AM EDT)June 10;July 10 5924 (2001 9:00 AM EDT)June 10;July 10 5925 Note: Since none of the BYDAY, BYMONTHDAY or BYYEARDAY components 5926 are specified, the day is gotten from DTSTART 5928 Every other year on January, February, and March for 10 occurrences: 5930 DTSTART;TZID=US-Eastern:19970310T090000 5931 RRULE:FREQ=YEARLY;INTERVAL=2;COUNT=10;BYMONTH=1,2,3 5933 ==> (1997 9:00 AM EST)March 10 5934 (1999 9:00 AM EST)January 10;February 10;March 10 5935 (2001 9:00 AM EST)January 10;February 10;March 10 5936 (2003 9:00 AM EST)January 10;February 10;March 10 5938 Every 3rd year on the 1st, 100th and 200th day for 10 occurrences: 5940 DTSTART;TZID=US-Eastern:19970101T090000 5941 RRULE:FREQ=YEARLY;INTERVAL=3;COUNT=10;BYYEARDAY=1,100,200 5943 ==> (1997 9:00 AM EST)January 1 5944 (1997 9:00 AM EDT)April 10;July 19 5945 (2000 9:00 AM EST)January 1 5946 (2000 9:00 AM EDT)April 9;July 18 5947 (2003 9:00 AM EST)January 1 5948 (2003 9:00 AM EDT)April 10;July 19 5950 Dawson/Stenerson 110 Expires February 1999 5951 (2006 9:00 AM EST)January 1 5953 Every 20th Monday of the year, forever: 5955 DTSTART;TZID=US-Eastern:19970519T090000 5956 RRULE:FREQ=YEARLY;BYDAY=20MO 5958 ==> (1997 9:00 AM EDT)May 19 5959 (1998 9:00 AM EDT)May 18 5960 (1999 9:00 AM EDT)May 17 5961 ... 5963 Monday of week number 20 (where the default start of the week is 5964 Monday), forever: 5966 DTSTART;TZID=US-Eastern:19970512T090000 5967 RRULE:FREQ=YEARLY;BYWEEKNO=20;BYDAY=MO 5969 ==> (1997 9:00 AM EDT)May 12 5970 (1998 9:00 AM EDT)May 11 5971 (1999 9:00 AM EDT)May 17 5972 ... 5974 Every Thursday in March, forever: 5976 DTSTART;TZID=US-Eastern:19970313T090000 5977 RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=TH 5979 ==> (1997 9:00 AM EST)March 13,20,27 5980 (1998 9:00 AM EST)March 5,12,19,26 5981 (1999 9:00 AM EST)March 4,11,18,25 5982 ... 5984 Every Thursday, but only during June, July, and August, forever: 5986 DTSTART;TZID=US-Eastern:19970605T090000 5987 RRULE:FREQ=YEARLY;BYDAY=TH;BYMONTH=6,7,8 5989 ==> (1997 9:00 AM EDT)June 5,12,19,26;July 3,10,17,24,31; 5990 August 7,14,21,28 5991 (1998 9:00 AM EDT)June 4,11,18,25;July 2,9,16,23,30; 5992 August 6,13,20,27 5993 (1999 9:00 AM EDT)June 3,10,17,24;July 1,8,15,22,29; 5994 August 5,12,19,26 5995 ... 5997 Every Friday the 13th, forever: 5999 DTSTART;TZID=US-Eastern:19970902T090000 6000 EXDATE;TZID=US-Eastern:19970902T090000 6001 RRULE:FREQ=MONTHLY;BYDAY=FR;BYMONTHDAY=13 6003 ==> (1998 9:00 AM EST)February 13;March 13;November 13 6004 (1999 9:00 AM EDT)August 13 6006 Dawson/Stenerson 111 Expires February 1999 6007 (2000 9:00 AM EDT)October 13 6008 ... 6010 The first Saturday that follows the first Sunday of the month, 6011 forever: 6013 DTSTART;TZID=US-Eastern:19970913T090000 6014 RRULE:FREQ=MONTHLY;BYDAY=SA;BYMONTHDAY=7,8,9,10,11,12,13 6016 ==> (1997 9:00 AM EDT)September 13;October 11 6017 (1997 9:00 AM EST)November 8;December 13 6018 (1998 9:00 AM EST)January 10;February 7;March 7 6019 (1998 9:00 AM EDT)April 11;May 9;June 13... 6020 ... 6022 Every four years, the first Tuesday after a Monday in November, 6023 forever (U.S. Presidential Election day): 6025 DTSTART;TZID=US-Eastern:19961105T090000 6026 RRULE:FREQ=YEARLY;INTERVAL=4;BYMONTH=11;BYDAY=TU;BYMONTHDAY=2,3,4, 6027 5,6,7,8 6029 ==> (1996 9:00 AM EST)November 5 6030 (2000 9:00 AM EST)November 7 6031 (2004 9:00 AM EST)November 2 6032 ... 6034 The 3rd instance into the month of one of Tuesday, Wednesday or 6035 Thursday, for the next 3 months: 6037 DTSTART;TZID=US-Eastern:19970904T090000 6038 RRULE:FREQ=MONTHLY;COUNT=3;BYDAY=TU,WE,TH;BYSETPOS=3 6040 ==> (1997 9:00 AM EDT)September 4;October 7 6041 (1997 9:00 AM EST)November 6 6043 The 2nd to last weekday of the month: 6045 DTSTART;TZID=US-Eastern:19970929T090000 6046 RRULE:FREQ=MONTHLY;BYDAY=MO,TU,WE,TH,FR;BYSETPOS=-2 6048 ==> (1997 9:00 AM EDT)September 29 6049 (1997 9:00 AM EST)October 30;November 27;December 30 6050 (1998 9:00 AM EST)January 29;February 26;March 30 6051 ... 6053 Every 3 hours from 9:00 AM to 5:00 PM on a specific day: 6055 DTSTART;TZID=US-Eastern:19970902T090000 6056 RRULE:FREQ=HOURLY;INTERVAL=3;UNTIL=19970902T170000Z 6058 ==> (September 2, 1997 EDT)09:00,12:00,15:00 6060 Every 15 minutes for 6 occurrences: 6062 Dawson/Stenerson 112 Expires February 1999 6063 DTSTART;TZID=US-Eastern:19970902T090000 6064 RRULE:FREQ=MINUTELY;INTERVAL=15;COUNT=6 6066 ==> (September 2, 1997 EDT)09:00,09:15,09:30,09:45,10:00,10:15 6068 Every hour and a half for 4 occurrences: 6070 DTSTART;TZID=US-Eastern:19970902T090000 6071 RRULE:FREQ=MINUTELY;INTERVAL=90;COUNT=4 6073 ==> (September 2, 1997 EDT)09:00,10:30;12:00;13:30 6075 Every 20 minutes from 9:00 AM to 4:40 PM every day: 6077 DTSTART;TZID=US-Eastern:19970902T090000 6078 RRULE:FREQ=DAILY;BYHOUR=9,10,11,12,13,14,15,16;BYMINUTE=0,20,40 6079 or 6080 RRULE:FREQ=MINUTELY;INTERVAL=20;BYHOUR=9,10,11,12,13,14,15,16 6082 ==> (September 2, 1997 EDT)9:00,9:20,9:40,10:00,10:20, 6083 ... 16:00,16:20,16:40 6084 (September 3, 1997 EDT)9:00,9:20,9:40,10:00,10:20, 6085 ...16:00,16:20,16:40 6086 ... 6088 An example where the days generated makes a difference because of 6089 WKST: 6091 DTSTART;TZID=US-Eastern:19970805T090000 6092 RRULE:FREQ=WEEKLY;INTERVAL=2;COUNT=4;BYDAY=TU,SU;WKST=MO 6094 ==> (1997 EDT)Aug 5,10,19,24 6096 changing only WKST from MO to SU, yields different results... 6098 DTSTART;TZID=US-Eastern:19970805T090000 6099 RRULE:FREQ=WEEKLY;INTERVAL=2;COUNT=4;BYDAY=TU,SU;WKST=SU 6100 ==> (1997 EDT)August 5,17,19,31 6102 4.8.6 Alarm Component Properties 6104 The following properties specify alarm information in calendar 6105 components. 6107 4.8.6.1 Action 6109 Property Name: ACTION 6111 Purpose: This property defines the action to be invoked when an alarm 6112 is triggered. 6114 Value Type: TEXT 6116 Dawson/Stenerson 113 Expires February 1999 6117 Property Parameters: Non-standard property parameters can be 6118 specified on this property. 6120 Conformance: This property MUST be specified once in a "VALARM" 6121 calendar component. 6123 Description: Each "VALARM" calendar component has a particular type 6124 of action associated with it. This property specifies the type of 6125 action 6127 Format Definition: The property is defined by the following notation: 6129 action = "ACTION" actionparam ":" actionvalue CRLF 6131 actionparam = *(";" xparam) 6133 actionvalue = "AUDIO" / "DISPLAY" / "EMAIL" / "PROCEDURE" 6134 / iana-token / x-name 6136 Example: The following are examples of this property in a "VALARM" 6137 calendar component: 6139 ACTION:AUDIO 6141 ACTION:DISPLAY 6143 ACTION:PROCEDURE 6145 4.8.6.2 Repeat Count 6147 Property Name: REPEAT 6149 Purpose: This property defines the number of time the alarm should be 6150 repeated, after the initial trigger. 6152 Value Type: INTEGER 6154 Property Parameters: Non-standard property parameters can be 6155 specified on this property. 6157 Conformance: This property can be specified in a "VALARM" calendar 6158 component. 6160 Description: If the alarm triggers more than once, then this property 6161 MUST be specified along with the "DURATION" property. 6163 Format Definition: The property is defined by the following notation: 6165 repeatcnt = "REPEAT" repparam ":" integer CRLF 6166 ;Default is "0", zero. 6168 repparam = *(";" xparam) 6170 Dawson/Stenerson 114 Expires February 1999 6171 Example: The following is an example of this property for an alarm 6172 that repeats 4 additional times with a 5 minute delay after the 6173 initial triggering of the alarm: 6175 REPEAT:4 6176 DURATION:PT5M 6178 4.8.6.3 Trigger 6180 Property Name: TRIGGER 6182 Purpose: This property specifies when an alarm will trigger. 6184 Value Type: The default value type is DURATION. The value type can be 6185 set to a DATE-TIME value type, in which case the value MUST specify a 6186 UTC formatted DATE-TIME value. 6188 Property Parameters: Non-standard, value data type, time zone 6189 identifier or trigger relationship property parameters can be 6190 specified on this property. The trigger relationship property 6191 parameter MUST only be specified when the value type is DURATION. 6193 Conformance: This property MUST be specified in the "VALARM" calendar 6194 component. 6196 Description: Within the "VALARM" calendar component, this property 6197 defines when the alarm will trigger. The default value type is 6198 DURATION, specifying a relative time for the trigger of the alarm. 6199 The default duration is relative to the start of an event or to-do 6200 that the alarm is associated with. The duration can be explicitly set 6201 to trigger from either the end or the start of the associated event 6202 or to-do with the "RELATED" parameter. A value of START will set the 6203 alarm to trigger off the start of the associated event or to-do. A 6204 value of END will set the alarm to trigger off the end of the 6205 associated event or to-do. 6207 Either a positive or negative duration may be specified for the 6208 "TRIGGER" property. An alarm with a positive duration is triggered 6209 after the associated start or end of the event or to-do. An alarm 6210 with a negative duration is triggered before the associated start or 6211 end of the event or to-do. 6213 The "RELATED" property parameter is not valid if the value type of 6214 the property is set to DATE-TIME (i.e., for an absolute date and time 6215 alarm trigger). If a value type of DATE-TIME is specified, then the 6216 property value MUST be specified in the UTC time format. If an 6217 absolute trigger is specified on an alarm for a recurring event or 6218 to-do, then the alarm will only trigger for the specified absolute 6219 date/time, along with any specified repeating instances. 6221 If the trigger is set relative to START, then the "DTSTART" property 6222 MUST be present in the associated "VEVENT" or "VTODO" calendar 6223 component. If an alarm is specified for an event with the trigger set 6225 Dawson/Stenerson 115 Expires February 1999 6226 relative to the END, then the "DTEND" property or the "DSTART" and 6227 "DURATION' properties MUST be present in the associated "VEVENT" 6228 calendar component. If the alarm is specified for a to-do with a 6229 trigger set relative to the END, then either the "DUE" property or 6230 the "DSTART" and "DURATION' properties MUST be present in the 6231 associated "VTODO" calendar component. 6233 Alarms specified in an event or to-do which is defined in terms of a 6234 DATE value type will be triggered relative to 00:00:00 UTC on the 6235 specified date. For example, if "DTSTART:19980205, then the duration 6236 trigger will be relative to19980205T000000Z. 6238 Format Definition: The property is defined by the following notation: 6240 trigger = "TRIGGER" (trigrel / trigabs) 6242 trigrel = *( 6244 ; the following are optional, 6245 ; but MUST NOT occur more than once 6247 (";" "VALUE" "=" "DURATION") / 6248 (";" trigrelparam) / 6250 ; the following is optional, 6251 ; and MAY occur more than once 6253 (";" xparam) 6255 ) ":" dur-value 6257 trigabs = 1*( 6259 ; the following is REQUIRED, 6260 ; but MUST NOT occur more than once 6262 (";" "VALUE" "=" "DATE-TIME") / 6264 ; the following is optional, 6265 ; and MAY occur more than once 6267 (";" xparam) 6269 ) ":" date-time 6271 Example: A trigger set 15 minutes prior to the start of the event or 6272 to-do. 6274 TRIGGER:-P15M 6276 A trigger set 5 minutes after the end of the event or to-do. 6278 TRIGGER;RELATED=END:P5M 6280 Dawson/Stenerson 116 Expires February 1999 6281 A trigger set to an absolute date/time. 6283 TRIGGER;VALUE=DATE-TIME:19980101T050000Z 6285 4.8.7 Change Management Component Properties 6287 The following properties specify change management information in 6288 calendar components. 6290 4.8.7.1 Date/Time Created 6292 Property Name: CREATED 6294 Purpose: This property specifies the date and time that the calendar 6295 information was created by the calendar user agent in the calendar 6296 store. 6298 Note: This is analogous to the creation date and time for a file 6299 in the file system. 6301 Value Type: DATE-TIME 6303 Property Parameters: Non-standard property parameters can be 6304 specified on this property. 6306 Conformance: The property can be specified once in "VEVENT", "VTODO" 6307 or "VJOURNAL" calendar components. 6309 Description: The date and time is a UTC value. 6311 Format Definition: The property is defined by the following notation: 6313 created = "CREATED" creaparam ":" date-time CRLF 6315 creaparam = *(";" xparam) 6317 Example: The following is an example of this property: 6319 CREATED:19960329T133000Z 6321 4.8.7.2 Date/Time Stamp 6323 Property Name: DTSTAMP 6325 Purpose: The property indicates the date/time that the instance of 6326 the iCalendar object was created. 6328 Value Type: DATE-TIME 6330 Property Parameters: Non-standard property parameters can be 6331 specified on this property. 6333 Dawson/Stenerson 117 Expires February 1999 6334 Conformance: This property MUST be included in the "VEVENT", "VTODO", 6335 "VJOURNAL" or "VFREEBUSY" calendar components. 6337 Description: The value MUST be specified in the UTC time format. 6339 This property is also useful to protocols such as [IMIP] that have 6340 inherent latency issues with the delivery of content. This property 6341 will assist in the proper sequencing of messages containing iCalendar 6342 objects. 6344 This property is different than the "CREATED" and "LAST-MODIFIED" 6345 properties. These two properties are used to specify when the 6346 particular calendar data in the calendar store was created and last 6347 modified. This is different than when the iCalendar object 6348 representation of the calendar service information was created or 6349 last modified. 6351 Format Definition: The property is defined by the following notation: 6353 dtstamp = "DTSTAMP" stmparam ":" date-time CRLF 6355 stmparam = *(";" xparam) 6357 Example: 6359 DTSTAMP:19971210T080000Z 6361 4.8.7.3 Last Modified 6363 Property Name: LAST-MODIFIED 6365 Purpose: The property specifies the date and time that the 6366 information associated with the calendar component was last revised 6367 in the calendar store. 6369 Note: This is analogous to the modification date and time for a 6370 file in the file system. 6372 Value Type: DATE-TIME 6374 Property Parameters: Non-standard property parameters can be 6375 specified on this property. 6377 Conformance: This property can be specified in the "EVENT", "VTODO", 6378 "VJOURNAL" or "VTIMEZONE" calendar components. 6380 Description: The property value MUST be specified in the UTC time 6381 format. 6383 Format Definition: The property is defined by the following notation: 6385 last-mod = "LAST-MODIFIED" lstparam ":" date-time CRLF 6387 Dawson/Stenerson 118 Expires February 1999 6388 lstparam = *(";" xparam) 6390 Example: The following is are examples of this property: 6392 LAST-MODIFIED:19960817T133000Z 6394 4.8.7.4 Sequence Number 6396 Property Name: SEQUENCE 6398 Purpose: This property defines the revision sequence number of the 6399 calendar component within a sequence of revisions. 6401 Value Type: integer 6403 Property Parameters: Non-standard property parameters can be 6404 specified on this property. 6406 Conformance: The property can be specified in "VEVENT", "VTODO" or 6407 "VJOURNAL" calendar component. 6409 Description: When a calendar component is created, its sequence 6410 number is zero (US-ASCII decimal 48). It is monotonically incremented 6411 by the "Organizer's" CUA each time the "Organizer" makes a 6412 significant revision to the calendar component. When the "Organizer" 6413 makes changes to one of the following properties, the sequence number 6414 MUST be incremented: 6416 @ "DTSTART" 6418 @ "DTEND" 6420 @ "DUE" 6422 @ "RDATE" 6424 @ "RRULE" 6426 @ "EXDATE" 6428 @ "EXRULE" 6430 @ "STATUS" 6432 In addition, changes made by the "Organizer" to other properties can 6433 also force the sequence number to be incremented. The "Organizer" CUA 6434 MUST increment the sequence number when ever it makes changes to 6435 properties in the calendar component that the "Organizer" deems will 6436 jeopardize the validity of the participation status of the 6437 "Attendees". For example, changing the location of a meeting from one 6438 locale to another distant locale could effectively impact the 6439 participation status of the "Attendees". 6441 Dawson/Stenerson 119 Expires February 1999 6442 The "Organizer" includes this property in an iCalendar object that it 6443 sends to an "Attendee" to specify the current version of the calendar 6444 component. 6446 The "Attendee" includes this property in an iCalendar object that it 6447 sends to the "Organizer" to specify the version of the calendar 6448 component that the "Attendee" is referring to. 6450 A change to the sequence number is not the mechanism that an 6451 "Organizer" uses to request a response from the "Attendees". The 6452 "RSVP" parameter on the "ATTENDEE" property is used by the 6453 "Organizer" to indicate that a response from the "Attendees" is 6454 requested. 6456 Format Definition: This property is defined by the following 6457 notation: 6459 seq = "SEQUENCE" seqparam ":" integer CRLF 6460 ; Default is "0" 6462 seqparam = *(";" xparam) 6464 Example: The following is an example of this property for a calendar 6465 component that was just created by the "Organizer". 6467 SEQUENCE:0 6469 The following is an example of this property for a calendar component 6470 that has been revised two different times by the "Organizer". 6472 SEQUENCE:2 6474 4.8.8 Miscellaneous Component Properties 6476 The following properties specify information about a number of 6477 miscellaneous features of calendar components. 6479 4.8.8.1 Non-standard Properties 6481 Property Name: Any property name with a "X-" prefix 6483 Purpose: This class of property provides a framework for defining 6484 non-standard properties. 6486 Value Type: TEXT 6488 Property Parameters: Non-standard and language property parameters 6489 can be specified on this property. 6491 Conformance: This property can be specified in any calendar 6492 component. 6494 Dawson/Stenerson 120 Expires February 1999 6495 Description: The MIME Calendaring and Scheduling Content Type 6496 provides a "standard mechanism for doing non-standard things". This 6497 extension support is provided for implementers to "push the envelope" 6498 on the existing version of the memo. Extension properties are 6499 specified by property and/or property parameter names that have the 6500 prefix text of "X-" (the two character sequence: LATIN CAPITAL LETTER 6501 X character followed by the HYPEN-MINUS character). It is recommended 6502 that vendors concatenate onto this sentinel another short prefix text 6503 to identify the vendor. This will facilitate readability of the 6504 extensions and minimize possible collision of names between different 6505 vendors. User agents that support this content type are expected to 6506 be able to parse the extension properties and property parameters but 6507 can ignore them. 6509 At present, there is no registration authority for names of extension 6510 properties and property parameters. The data type for this property 6511 is TEXT. Optionally, the data type can be any of the other valid data 6512 types. 6514 Format Definition: The property is defined by the following notation: 6516 x-prop = x-name *(";" xparam) [";" languageparam] ":" text CRLF 6517 ; Lines longer than 75 octets should be folded 6519 Example: The following might be the ABC vendor�s extension for an 6520 audio-clip form of subject property: 6522 X-ABC-MMSUBJ;X-ABC-MMSUBJTYPE=wave:http://load.noise.org/mysubj.wav 6524 4.8.8.2 Request Status 6526 Property Name: REQUEST-STATUS 6528 Purpose: This property defines the status code returned for a 6529 scheduling request. 6531 Value Type: TEXT 6533 Property Parameters: Non-standard and language property parameters 6534 can be specified on this property. 6536 Conformance: The property can be specified in "VEVENT", "VTODO", 6537 "VJOURNAL" or "VFREEBUSY" calendar component. 6539 Description: This property is used to return status code information 6540 related to the processing of an associated iCalendar object. The data 6541 type for this property is TEXT. 6543 The value consists of a short return status component, a longer 6544 return status description component, and optionally a status-specific 6545 data component. The components of the value are separated by the 6546 SEMICOLON character (US-ASCII decimal 59). 6548 Dawson/Stenerson 121 Expires February 1999 6549 The short return status is a PERIOD character (US-ASCII decimal 46) 6550 separated 3-tuple of integers. For example, "3.1.1". The successive 6551 levels of integers provide for a successive level of status code 6552 granularity. 6554 The following are initial classes for the return status code. 6555 Individual iCalendar object methods will define specific return 6556 status codes for these classes. In addition, other classes for the 6557 return status code may be defined using the registration process 6558 defined later in this memo. 6560 |==============+===============================================| 6561 | Short Return | Longer Return Status Description | 6562 | Status Code | | 6563 |==============+===============================================| 6564 | 1.xx | Preliminary success. This class of status | 6565 | | of status code indicates that the request has | 6566 | | request has been initially processed but that | 6567 | | completion is pending. | 6568 |==============+===============================================| 6569 | 2.xx | Successful. This class of status code | 6570 | | indicates that the request was completed | 6571 | | successfuly. However, the exact status code | 6572 | | can indicate that a fallback has been taken. | 6573 |==============+===============================================| 6574 | 3.xx | Client Error. This class of status code | 6575 | | indicates that the request was not successful.| 6576 | | The error is the result of either a syntax or | 6577 | | a semantic error in the client formatted | 6578 | | request. Request should not be retried until | 6579 | | the condition in the request is corrected. | 6580 |==============+===============================================| 6581 | 4.xx | Scheduling Error. This class of status code | 6582 | | indicates that the request was not successful.| 6583 | | Some sort of error occurred within the | 6584 | | calendaring and scheduling service, not | 6585 | | directly related to the request itself. | 6586 |==============+===============================================| 6588 Format Definition: The property is defined by the following notation: 6590 rstatus = "REQUEST-STATUS" rstatparam ":" 6591 statcode ";" statdesc [";" extdata] 6593 rstatparam = *( 6595 ; the following is optional, 6596 ; but MUST NOT occur more than once 6598 (";" languageparm) / 6600 ; the following is optional, 6601 ; and MAY occur more than once 6603 Dawson/Stenerson 122 Expires February 1999 6604 (";" xparam) 6606 ) 6608 statcode = 1*DIGIT *("." 1*DIGIT) 6609 ;Hierarchical, numeric return status code 6611 statdesc = text 6612 ;Textual status description 6614 extdata = text 6615 ;Textual exception data. For example, the offending property 6616 ;name and value or complete property line. 6618 Example: The following are some possible examples of this property. 6619 The COMMA and SEMICOLON separator characters in the property value 6620 are BACKSLASH character escaped because they appear in a text value. 6622 REQUEST-STATUS:2.0;Success 6624 REQUEST-STATUS:3.1;Invalid property value;DTSTART:96-Apr-01 6626 REQUEST-STATUS:2.8; Success\, repeating event ignored. Scheduled 6627 as a single event.;RRULE:FREQ=WEEKLY\;INTERVAL=2 6629 REQUEST-STATUS:4.1;Event conflict. Date/time is busy. 6631 REQUEST-STATUS:3.7;Invalid calendar user;ATTENDEE: 6632 MAILTO:jsmith@host.com 6634 5 iCalendar Object Examples 6636 The following examples are provided as an informational source of 6637 illustrative iCalendar objects consistent with this content type. 6639 The following example specifies a three-day conference that begins at 6640 8:00 AM EDT, September 18, 1996 and end at 6:00 PM EDT, September 20, 6641 1996. 6643 BEGIN:VCALENDAR 6644 PRODID:-//xyz Corp//NONSGML PDA Calendar Verson 1.0//EN 6645 VERSION:2.0 6646 BEGIN:VEVENT 6647 DTSTAMP:19960704T120000Z 6648 UID:uid1@host.com 6649 ORGANIZER:MAILTO:jsmith@host.com 6650 DTSTART:19960918T143000Z 6651 DTEND:19960920T220000Z 6652 STATUS:CONFIRMED 6653 CATEGORIES:CONFERENCE 6654 SUMMARY:Networld+Interop Conference 6655 DESCRIPTION:Networld+Interop Conference 6656 and Exhibit\nAtlanta World Congress Center\n 6658 Dawson/Stenerson 123 Expires February 1999 6659 Atlanta, Georgia 6660 END:VEVENT 6661 END:VCALENDAR 6663 The following example specifies a group scheduled meeting that begin 6664 at 8:30 AM EST on March 12, 1998 and end at 9:30 AM EST on March 12, 6665 1998. The "Organizer" has scheduled the meeting with one or more 6666 calendar users in a group. A time zone specification for Eastern 6667 United States has been specified. 6669 BEGIN:VCALENDAR 6670 PRODID:-//RDU Software//NONSGML HandCal//EN 6671 VERSION:2.0 6672 BEGIN:VTIMEZONE 6673 TZID:US-Eastern 6674 BEGIN:STANDARD 6675 DTSTART:19981025T020000 6676 RDATE:19981025T020000 6677 TZOFFSETFROM:-0400 6678 TZOFFSETTO:-0500 6679 TZNAME:EST 6680 END:STANDARD 6681 BEGIN:DAYLIGHT 6682 DTSTART:19990404T020000 6683 RDATE:19990404T020000 6684 TZOFFSETFROM:-0500 6685 TZOFFSETTO:-0400 6686 TZNAME:EDT 6687 END:DAYLIGHT 6688 END:VTIMEZONE 6689 BEGIN:VEVENT 6690 DTSTAMP:19980309T231000Z 6691 UID:guid-1.host1.com 6692 ORGANIZER;ROLE=CHAIR:MAILTO:mrbig@host.com 6693 ATTENDEE;RSVP=TRUE;ROLE=REQ-PARTICIPANT;CUTYPE=GROUP: 6694 MAILTO:employee-A@host.com 6695 DESCRIPTION:Project XYZ Review Meeting 6696 CATEGORIES:MEETING 6697 CLASS:PUBLIC 6698 CREATED:19980309T130000Z 6699 SUMMARY:XYZ Project Review 6700 DTSTART;TZID=US-Eastern:19980312T083000 6701 DTEND;TZID=US-Eastern:19980312T093000 6702 LOCATION:1CP Conference Room 4350 6703 END:VEVENT 6704 END:VCALENDAR 6706 The following is an example of an iCalendar object passed in a MIME 6707 message with a single body part consisting of a "text/calendar" 6708 Content Type. 6710 TO:jsmith@host1.com 6711 FROM:jdoe@host1.com 6713 Dawson/Stenerson 124 Expires February 1999 6714 MIME-VERSION:1.0 6715 MESSAGE-ID: 6716 CONTENT-TYPE:text/calendar 6718 BEGIN:VCALENDAR 6719 METHOD:xyz 6720 VERSION:2.0 6721 PRODID:-//ABC Corporation//NONSGML My Product//EN 6722 BEGIN:VEVENT 6723 DTSTAMP:19970324T1200Z 6724 SEQUENCE:0 6725 UID:uid3@host1.com 6726 ORGANIZER:MAILTO:jdoe@host1.com 6727 ATTENDEE;RSVP=TRUE:MAILTO:jsmith@host1.com 6728 DTSTART:19970324T123000Z 6729 DTEND:19970324T210000Z 6730 CATEGORIES:MEETING,PROJECT 6731 CLASS:PUBLIC 6732 SUMMARY:Calendaring Interoperability Planning Meeting 6733 DESCRIPTION:Discuss how we can test c&s interoperability\n 6734 using iCalendar and other IETF standards. 6735 LOCATION:LDB Lobby 6736 ATTACH;FMTTYPE=application/postscript:ftp://xyzCorp.com/pub/ 6737 conf/bkgrnd.ps 6738 END:VEVENT 6739 END:VCALENDAR 6741 The following is an example of a to-do due on April 15, 1998. An 6742 audio alarm has been specified to remind the calendar user at noon, 6743 the day before the to-do is expected to be completed and repeat 6744 hourly, four additional times. The to-do definition has been modified 6745 twice since it was initially created. 6747 BEGIN:VCALENDAR 6748 VERSION:2.0 6749 PRODID:-//ABC Corporation//NONSGML My Product//EN 6750 BEGIN:VTODO 6751 DTSTAMP:19980130T134500Z 6752 SEQUENCE:2 6753 UID:uid4@host1.com 6754 ORGANIZER:MAILTO:unclesam@us.gov 6755 ATTENDEE;PARTSTAT=ACCEPTED:MAILTO:jqpublic@host.com 6756 DUE:19980415T235959 6757 STATUS:NEEDS-ACTION 6758 SUMMARY:Submit Income Taxes 6759 BEGIN:VALARM 6760 ACTION:AUDIO 6761 TRIGGER:19980403T120000 6762 ATTACH;FMTTYPE=audio/basic:http://host.com/pub/audio- 6763 files/ssbanner.aud 6764 REPEAT:4 6765 DURATION:PT1H 6766 END:VALARM 6768 Dawson/Stenerson 125 Expires February 1999 6769 END:VTODO 6770 END:VCALENDAR 6772 The following is an example of a journal entry. 6774 BEGIN:VCALENDAR 6775 VERSION:2.0 6776 PRODID:-//ABC Corporation//NONSGML My Product//EN 6777 BEGIN:VJOURNAL 6778 DTSTAMP:19970324T120000Z 6779 UID:uid5@host1.com 6780 ORGANIZER:MAILTO:jsmith@host.com 6781 STATUS:DRAFT 6782 CLASS:PUBLIC 6783 CATEGORY:Project Report, XYZ, Weekly Meeting 6784 DESCRIPTION:Project xyz Review Meeting Minutes\n 6785 Agenda\n1. Review of project version 1.0 requirements.\n2. 6786 Definition 6787 of project processes.\n3. Review of project schedule.\n 6788 Participants: John Smith, Jane Doe, Jim Dandy\n-It was 6789 decided that the requirements need to be signed off by 6790 product marketing.\n-Project processes were accepted.\n 6791 -Project schedule needs to account for scheduled holidays 6792 and employee vacation time. Check with HR for specific 6793 dates.\n-New schedule will be distributed by Friday.\n- 6794 Next weeks meeting is cancelled. No meeting until 3/23. 6795 END:VJOURNAL 6796 END:VCALENDAR 6798 The following is an example of published busy time information. The 6799 iCalendar object might be placed in the network resource 6800 www.host.com/calendar/busytime/jsmith.ifb. 6802 BEGIN:VCALENDAR 6803 VERSION:2.0 6804 PRODID:-//RDU Software//NONSGML HandCal//EN 6805 BEGIN:VFREEBUSY 6806 ORGANIZER:MAILTO:jsmith@host.com 6807 DTSTART:19980313T141711Z 6808 DTEND:19980410T141711Z 6809 FREEBUSY:19980314T233000Z/19980315T003000Z 6810 FREEBUSY:19980316T153000Z/19980316T163000Z 6811 FREEBUSY:19980318T030000Z/19980318T040000Z 6812 URL:http://www.host.com/calendar/busytime/jsmith.ifb 6813 END:VFREEBUSY 6814 END:VCALENDAR 6816 6 Recommended Practices 6818 These recommended practices should be followed in order to assure 6819 consistent handling of the following cases for an iCalendar object. 6821 1. 6822 Content lines longer than 75 octets SHOULD be folded. 6824 Dawson/Stenerson 126 Expires February 1999 6825 2. 6826 A calendar entry with a "DTSTART" property but no "DTEND" property 6827 does not take up any time. It is intended to represent an event 6828 that is associated with a given calendar date and time of day, 6829 such as an anniversary. Since the event does not take up any time, 6830 it MUST NOT be used to record busy time no matter what the value 6831 for the "TRANSP" property. 6833 3. 6834 When the "DTSTART" and "DTEND", for "VEVENT", "VJOURNAL" and 6835 "VFREEBUSY" calendar components, and "DTSTART" and "DUE", for 6836 "VTODO" calendar components, have the same value data type (e.g., 6837 DATE-TIME), they SHOULD specify values in the same time format 6838 (e.g., UTC time format). 6840 4. 6841 When the combination of the "RRULE" and "RDATE" properties on an 6842 iCalendar object produces multiple instances having the same start 6843 date/time, they should be collapsed to, and considered as, a 6844 single instance. 6846 5. 6847 When a calendar user receives multiple requests for the same 6848 calendar component (e.g., REQUEST for a "VEVENT" calendar 6849 component) as a result of being on multiple mailing lists 6850 specified by "ATTENDEE" properties in the request, they SHOULD 6851 respond to only one of the requests. The calendar user SHOULD also 6852 specify (using the "MEMBER" parameter of the "ATTENDEE" property) 6853 which mailing list they are a member of. 6855 6. 6856 An implementation can truncate a "SUMMARY" property value to 255 6857 characters. 6859 7. 6860 If seconds of the minute are not supported by an implementation, 6861 then a value of "00" SHOULD be specified for the seconds component 6862 in a time value. 6864 8. 6865 If the value type parameter (VALUE=) contains an unknown value 6866 type, it SHOULD be treated as TEXT. 6868 9. 6869 TZURL values SHOULD NOT be specified as a FILE URI type. This URI 6870 form can be useful within an organization, but is problematic in 6871 the Internet. 6873 10. Some possible English values for CATEGORIES property include 6874 "ANNIVERSARY", "APPOINTMENT", "BUSINESS", "EDUCATION", "HOLIDAY", 6875 "MEETING", "MISCELLANEOUS", "NON-WORKING HOURS", "NOT IN OFFICE", 6876 "PERSONAL", "PHONE CALL", "SICK DAY", "SPECIAL OCCASION", 6877 "TRAVEL", "VACATION". Categories can be specified in any 6878 registered language. 6880 11. Some possible English values for RESOURCES property include 6881 "CATERING", "CHAIRS", "COMPUTER PROJECTOR", "EASEL", "OVERHEAD 6882 PROJECTOR", "SPEAKER PHONE", "TABLE", "TV", "VCR", "VIDEO PHONE", 6883 "VEHICLE". Resources can be specified in any registered language. 6885 Dawson/Stenerson 127 Expires February 1999 6886 7 Registration of Content Type Elements 6888 This section provides the process for registration of MIME 6889 Calendaring and Scheduling Content Type iCalendar object methods and 6890 new or modified properties. 6892 7.1 Registration of New and Modified iCalendar Object Methods 6894 New MIME Calendaring and Scheduling Content Type iCalendar object 6895 methods are registered by the publication of an IETF Request for 6896 Comment (RFC). Changes to an iCalendar object method are registered 6897 by the publication of a revision of the RFC defining the method. 6899 7.2 Registration of New Properties 6901 This section defines procedures by which new properties or enumerated 6902 property values for the MIME Calendaring and Scheduling Content Type 6903 can be registered with the IANA. Non-IANA properties can be used by 6904 bilateral agreement, provided the associated properties names follow 6905 the "X-" convention. 6907 The procedures defined here are designed to allow public comment and 6908 review of new properties, while posing only a small impediment to the 6909 definition of new properties. 6911 Registration of a new property is accomplished by the following 6912 steps. 6914 7.2.1 Define the property 6916 A property is defined by completing the following template. 6918 To: ietf-calendar@imc.org 6920 Subject: Registration of text/calendar MIME property XXX 6922 Property name: 6924 Property purpose: 6926 Property value type(s): 6928 Property parameter (s): 6930 Conformance: 6932 Description: 6934 Format definition: 6936 Examples: 6938 The meaning of each field in the template is as follows. 6940 Dawson/Stenerson 128 Expires February 1999 6941 Property name: The name of the property, as it will appear in the 6942 body of an text/calendar MIME Content-Type "property: value" line to 6943 the left of the colon ":". 6945 Property purpose: The purpose of the property (e.g., to indicate a 6946 delegate for the event or to-do, etc.). Give a short but clear 6947 description. 6949 Property value type (s): Any of the valid value types for the 6950 property value needs to be specified. The default value type also 6951 needs to be specified. If a new value type is specified, it needs to 6952 be declared in this section. 6954 Property parameter (s): Any of the valid property parameters for the 6955 property needs to be specified. 6957 Conformance: The calendar components that the property can appear in 6958 needs to be specified. 6960 Description: Any special notes about the property, how it is to be 6961 used, etc. 6963 Format definition: The ABNF for the property definition needs to be 6964 specified. 6966 Examples: One or more examples of instances of the property needs to 6967 be specified. 6969 7.2.2 Post the Property definition 6971 The property description MUST be posted to the new property 6972 discussion list, ietf-calendar@imc.org. 6974 7.2.3 Allow a comment period 6976 Discussion on the new property MUST be allowed to take place on the 6977 list for a minimum of two weeks. Consensus MUST be reached on the 6978 property before proceeding to the next step. 6980 7.2.4 Submit the property for approval 6982 Once the two-week comment period has elapsed, and the proposer is 6983 convinced consensus has been reached on the property, the 6984 registration application should be submitted to the Method Reviewer 6985 for approval. The Method Reviewer is appointed to the Application 6986 Area Directors and can either accept or reject the property 6987 registration. An accepted registration should be passed on by the 6988 Method Reviewer to the IANA for inclusion in the official IANA method 6989 registry. The registration can be rejected for any of the following 6990 reasons. 1) Insufficient comment period; 2) Consensus not reached; 3) 6991 Technical deficiencies raised on the list or elsewhere have not been 6992 addressed. The Method Reviewer's decision to reject a property can be 6994 Dawson/Stenerson 129 Expires February 1999 6995 appealed by the proposer to the IESG, or the objections raised can be 6996 addressed by the proposer and the property resubmitted. 6998 7.3 Property Change Control 7000 Existing properties can be changed using the same process by which 7001 they were registered. 7003 1. 7004 Define the change 7006 2. 7007 Post the change 7009 3. 7010 Allow a comment period 7012 4. 7013 Submit the property for approval 7015 Note that the original author or any other interested party can 7016 propose a change to an existing property, but that such changes 7017 should only be proposed when there are serious omissions or errors in 7018 the published memo. The Method Reviewer can object to a change if it 7019 is not backward compatible, but is not required to do so. 7021 Property definitions can never be deleted from the IANA registry, but 7022 properties which are no longer believed to be useful can be declared 7023 OBSOLETE by a change to their "intended use" field. 7025 8 References 7027 The following documents are referred to within this memo. 7029 [ICMS] "Internet Calendaring Model Specification", Internet-Draft, 7030 October 1997, ftp://ftp.ietf.org/internet-drafts/draft-ietf-calsch- 7031 mod-03.txt. 7033 [IMIP] "iCalendar Message-based Interoperability Protocol (IMIP)", 7034 Internet Draft, April 1998, http://www.imc.org/draft-ietf-calsch- 7035 imip-05.txt. 7037 [ITIP] "iCalendar Transport-Independent Interoperability Protocol 7038 (iTIP) : Scheduling Events, Busy Time, To-dos and Journal Entries ", 7039 Internet-Draft, April 1998, http://www.imc.org/draft-ietf-calsch- 7040 itip-05.txt. 7042 [ISO 8601] ISO 8601, "Data elements and interchange formats� 7043 Information interchange--Representation of dates and times", 7044 International Organization for Standardization, June, 1988. This 7045 standard is also addressed by the Internet Draft document 7046 ftp://ds.internic.net/internet-drafts/draft-newman-datetime-00.txt. 7048 [ISO 9070] ISO/IEC 9070, "Information Technology�SGML Support 7049 Facilities--Registration Procedures for Public Text Owner 7050 Identifiers", Second Edition, International Organization for 7051 Standardization, April 1991. 7053 Dawson/Stenerson 130 Expires February 1999 7055 [MIME DIR] Howes, T., Smith, M., "A MIME Content-Type for Directory 7056 Information", Internet-draft-ietf-asid-mime-direct-07.txt, November 7057 1997. 7059 [RFC 822] Crocker, D., "Standard for the Format of ARPA Internet Text 7060 Messages", STD 11, RFC 822, August 1982. 7062 [RFC 1738] Berners-Lee, T., Masinter, L., McCahill, M., "Uniform 7063 Resource Locators (URL)", RFC 1738, December 1994. 7065 [RFC 1766] Alvestrand, H., "Tags for the Identification of 7066 Languages", March 1995. 7068 [RFC 2045] Freed, N., Borenstein, N., " Multipurpose Internet Mail 7069 Extensions (MIME) - Part One: Format of Internet Message Bodies", RFC 7070 2045, November 1996. 7072 [RFC 2046] Freed, N., Borenstein, N., " Multipurpose Internet Mail 7073 Extensions (MIME) - Part Two: Media Types", RFC 2046, November 1996. 7075 [RFC 2047] Moore, K., "Multipurpose Internet Mail Extensions (MIME) - 7076 Part Three: Message Header Extensions for Non-ASCII Text", RFC 2047, 7077 November 1996. 7079 [RFC 2048] Freed, N., J. Klensin, J. Postel, "Multipurpose Internet 7080 Mail Extensions (MIME) - Part Four: Registration Procedures", RFC 7081 2048, January 1997. 7083 [RFC 2111] "Content-ID and Message-ID Uniform Resource Locators", RFC 7084 2111, March 1997. 7086 [RFC 2119] "Key words for use in RFCs to Indicate Requirement 7087 Levels", RFC 2119, March 1997. 7089 [RFC 2234] Crocker, D., Overell, P., "Augmented BNF for Syntax 7090 Specifications: ABNF", RFC 2234, November 1997. 7092 [RFC 2279] "UTF-8, a transformation format of ISO 10646", RFC 2279, 7093 January 1998. 7095 [TZ] Olson, A.D., et al, Time zone code and data, 7096 ftp://elsie.nci.nih.gov/pub/, updated periodically. 7098 [VCARD] Internet Mail Consortium, "vCard - The Electronic Business 7099 Card Version 2.1", http://www.imc.org/pdi/vcard-21.txt, September 7100 18, 1996. 7102 [VCAL] Internet Mail Consortium, "vCalendar - The Electronic 7103 Calendaring and Scheduling Exchange Format", 7104 http://www.imc.org/pdi/vcal-10.txt, September 18, 1996. 7106 [XAPIA] "XAPIA CSA, Calendaring and Scheduling Application 7107 Programming Interface (CSA) Version 1.0", X.400 API Association, 7108 November 15, 1994. 7110 Dawson/Stenerson 131 Expires February 1999 7111 9 Acknowledgments 7113 A hearty thanks to the IETF Calendaring and Scheduling Working Group 7114 and also the following individuals who have participated in the 7115 drafting, review and discussion of this memo: 7117 Roland Alden, Harald T. Alvestrand, Eric Berman, Denis Bigorgne, John 7118 Binici, Bill Bliss, Philippe Boucher, Steve Carter, Andre 7119 Courtemanche, Dave Crocker, David Curley, Alec Dun, John Evans, Ross 7120 Finlayson, Randell Flint, Ned Freed, Patrik Faltstrom, Chuck 7121 Grandgent, Mark Handley, Steve Hanna, Paul B. Hill, Paul Hoffman, 7122 Ross Hopson, Mark Horton, Daryl Huff, Bruce Kahn, C. Harald Koch, 7123 Ryan Jansen, Don Lavange, Antoine Leca, Theodore Lorek, Steve 7124 Mansour, Skip Montanaro, Keith Moore, Cecil Murray, Chris Newman, 7125 John Noerenberg, Ralph Patterson, Pete Resnick, Keith Rhodes, Robert 7126 Ripberger, John Rose, Doug Royer, Andras Salamar, Ted Schuh, Vinod 7127 Seraphin, Derrick Shadel, Ken Shan, Andrew Shuman, Steve Silverberg, 7128 William P. Spencer, John Sun, Mark Towfiq, Yvonne Tso, Robert Visnov, 7129 James L. Weiner, Mike Weston, William Wyatt. 7131 10 Authors' and Chairs' Addresses 7133 The following address information is provided in a MIME-VCARD, 7134 Electronic Business Card, format. 7136 The authors of this draft are: 7138 BEGIN:VCARD 7139 VERSION:3.0 7140 N:Dawson;Frank 7141 FN:Frank Dawson 7142 ORG:Lotus Development Corporation 7143 ADR;WORK;POSTAL;PARCEL:;6544 Battleford Drive; 7144 Raleigh;NC;27613-3502;USA 7145 TEL;WORK;MSG:+1-919-676-9515 7146 TEL;WORK;FAX:+1-919-676-9564 7147 EMAIL;INTERNET;PREF:Frank_Dawson@Lotus.com 7148 EMAIL;INTERNET:fdawson@earthlink.net 7149 URL:http://home.earthlink.net/~fdawson 7150 END:VCARD 7152 BEGIN:VCARD 7153 VERSION:3.0 7154 N:Stenerson;Derik 7155 FN:Derik Stenerson 7156 ORG:Microsoft Corporation 7157 ADR;WORK;POSTAL;PARCEL:;One Microsoft Way; 7158 Redmond;WA;98052-6399;USA 7159 TEL;WORK;MSG:+1-425-936-5522 7160 TEL;WORK;FAX:+1-425-936-7329 7161 EMAIL;INTERNET:deriks@Microsoft.com 7162 END:VCARD 7164 Dawson/Stenerson 132 Expires February 1999 7165 The iCalendar object is a result of the work of the Internet 7166 Engineering Task Force Calendaring and Scheduling Working Group. The 7167 chairman of that working group is: 7169 BEGIN:VCARD 7170 VERSION:2.1 7171 FN:Anik Ganguly 7172 ORG: Open Text Inc. 7173 ADR;WORK;POSTAL;PARCEL: 38777 West Six Mile Road;Suite 101; 7174 Livonia;MI; 48152;USA 7175 TEL;WORK;MSG:+1-734-542-5955 7176 EMAIL;INTERNET:ganguly@acm.org 7177 END:VCARD 7179 The co-chairman of that working group is: 7181 BEGIN:VCARD 7182 VERSION:2.1 7183 FN:Robert Moskowitz 7184 EMAIL;INTERNET: rgm-ietf@htt-consult.com 7185 END:VCARD 7187 11 Full Copyright Statement 7189 "Copyright (C) The Internet Society (date). All Rights Reserved. 7191 This document and translations of it may be copied and furnished to 7192 others, and derivative works that comment on or otherwise explain it 7193 or assist in its implmentation may be prepared, copied, published and 7194 distributed, in whole or in part, without restriction of any kind, 7195 provided that the above copyright notice and this paragraph are 7196 included on all such copies and derivative works. However, this 7197 document itself may not be modified in any way, such as by removing 7198 the copyright notice or references to the Internet Society or other 7199 Internet organizations, except as needed for the purpose of 7200 developing Internet standards in which case the procedures for 7201 copyrights defined in the Internet Standards process MUST be 7202 followed, or as required to translate it into languages other than 7203 English. 7205 The limited permissions granted above are perpetual and will not be 7206 revoked by the Internet Society or its successors or assigns. 7208 This document and the information contained herein is provided on an 7209 "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING 7210 TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING 7211 BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION 7212 HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF 7213 MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 7215 Dawson/Stenerson 133 Expires February 1999