Network Working Group Frank Dawson, Lotus Internet Draft Derik Stenerson, Microsoft February 3, 1997 Expires August 1997 Internet Calendaring and Scheduling Core Object Specification (iCalendar) Status of this Memo This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months. Internet-Drafts may be updated, replaced, or made obsolete by other documents at any time. It is not appropriate to use Internet- Drafts as reference material or to cite them other than as a "working draft" or "work in progress". To learn the current status of any Internet-Draft, please check the 1id-abstracts.txt listing contained in the Internet-Drafts Shadow Directories on ds.internic.net (US East Coast), nic.nordu.net (Europe), ftp.isi.edu (US West Coast), or munnari.oz.au (Pacific Rim). Distribution of this document is unlimited. Abstract There is a clear need to provide and deploy interoperable calendaring and scheduling services for the Internet. Current group scheduling and Personal Information Management (PIM) products are being extended for use across the Internet, today, in proprietary ways. This document has been defined to provide the a definition of a common format for openly exchanging calendaring and scheduling information across the Internet. This memo is formatted as a registration for a MIME media type per [RFC1521]. However, the format in this memo is equally applicable for use outside of a MIME message content type. [Editor NOTE: This form will be changed to reflect the new MIME memos in the next draft.] The proposed media type value is "TEXT/CALENDAR". This string would label a media type containing calendaring and scheduling information encoded as text characters formatted in a manner outlined below. This MIME media type provides a standard content type for capturing calendar event and to-do information. It also can be used to convey free/busy time information. The content type is suitable as a MIME message entity that can be transferred over MIME based email systems Dawson/Stenerson 1 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 or using HTTP. In addition, the content type is useful as an object for interactions between desktop applications using the operating system clipboard, drag/drop or file systems capabilities. This document is based on the earlier work of the vCalendar specification for the exchange of personal calendaring and scheduling information. In order to avoid confusion with this referenced work, this document is to be known as the iCalendar specification. This document also includes the format for defining content type profiles. A content type profile is a document that defines a set of usage constraints for the iCalendar Object. For example, a profile might be defined to specify how the iCalendar Object can be used to provide for a set of interpersonal scheduling messages. Such a profile might define scheduling messages that request an event be scheduled, reply to an event request, send a cancellation notice for an event, modify or replace the definition of an event, provide a counter proposal for an original event request, delegate an event request to another individual, request free or busy time, reply to a free or busy time request, or provide similar scheduling messages for a to-do calendar component. Table of Contents 1. Introduction........................................................4 1.1 Definitions ......................................................5 1.1.1 Calendar Scale ................................................5 1.1.2 Coordinate Universal Time (UTC) ...............................5 1.1.3 Daylight Saving Time (DST) ....................................5 1.1.4 Gregorian Calendar ............................................5 1.1.5 Local Time ....................................................5 1.1.6 Standard Time .................................................6 1.1.7 Time Zone .....................................................6 2. TEXT/CALENDAR Registration Information..............................6 3. Intended Use........................................................7 3.1 Published specification ..........................................8 3.1.1 Existing Message Header Fields ................................8 3.1.1.1 Content-Type Header Field .................................8 3.1.1.1.1 CHARSET Header Field Parameter .........................8 3.1.1.2 Content-ID Header Field ...................................9 3.1.1.3 Content-Language ..........................................9 3.1.1.4 Message-ID Header Field ...................................9 3.1.1.5 Transfer-Encoding Header Field ............................9 3.1.2 Additional Content Type Parameter .............................9 3.1.2.1 Profile ...................................................9 3.1.3 Content Syntax Considerations ................................10 3.1.3.1 Property .................................................10 3.1.3.2 Delimiters ...............................................11 3.1.3.3 Property Value Transfer Encoding .........................12 3.1.3.4 Property Value Character Set .............................12 3.1.3.5 Property Value Language ..................................13 3.1.3.6 Property Value Data Type .................................13 3.1.3.7 Date and Time ............................................16 3.1.3.8 Time Duration ............................................18 Dawson/Stenerson 2 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 3.1.3.9 Value Location ...........................................19 3.1.3.10 Binary Property Values ..................................19 3.1.3.11 Recurrence Rule Grammar .................................19 3.1.4 Body Delimiter Properties ....................................20 3.1.4.1 Calendar Object ..........................................20 3.1.4.2 Event Component ..........................................20 3.1.4.3 To-do Component ..........................................21 3.1.5 Calendar Object Properties ...................................21 3.1.5.1 Calendar Content Profile .................................21 3.1.5.2 Calendar Scale ...........................................24 3.1.5.3 Daylight Savings Rule ....................................24 3.1.5.4 Geographic Position ......................................25 3.1.5.5 Product Identifier .......................................25 3.1.5.6 Time Zone ................................................26 3.1.5.7 Version ..................................................26 3.1.6 Event and To-do Component Properties .........................26 3.1.6.1 Attachment ...............................................26 3.1.6.2 Attendee .................................................27 3.1.6.3 Audio Reminder ...........................................32 3.1.6.4 Categories ...............................................33 3.1.6.5 Classification ...........................................34 3.1.6.6 Date/Time Created ........................................35 3.1.6.7 Date/Time Completed ......................................35 3.1.6.8 Description ..............................................36 3.1.6.9 Display Reminder .........................................36 3.1.6.10 Due Date/Time ...........................................37 3.1.6.11 Duration ................................................37 3.1.6.12 End Date/Time ...........................................37 3.1.6.13 Exception Date/Times ....................................38 3.1.6.14 Exception Rule ..........................................38 3.1.6.15 Last Modified ...........................................38 3.1.6.16 Location ................................................39 3.1.6.17 Mail Reminder ...........................................39 3.1.6.18 Number Recurrences ......................................40 3.1.6.19 Priority ................................................40 3.1.6.20 Procedure Reminder ......................................40 3.1.6.21 Related To ..............................................41 3.1.6.22 Recurrence Date/Times ...................................41 3.1.6.23 Recurrence Rule .........................................42 3.1.6.24 Resources ...............................................42 3.1.6.25 Response Sequence Number ................................43 3.1.6.26 Sequence Number .........................................44 3.1.6.27 Start Date/Time .........................................44 3.1.6.28 Status ..................................................44 3.1.6.29 Summary .................................................46 3.1.6.30 Time Transparency .......................................46 3.1.6.31 Uniform Resource Locator ................................46 3.1.6.32 Unique Identifier .......................................46 3.1.6.33 Non-standard Properties .................................47 3.2 Formal Definition ...............................................47 3.3 Basic Recurrence Rule Grammar ...................................53 3.3.1 Daily Rule ...................................................53 3.3.2 Weekly Rule ..................................................54 3.3.3 Monthly Rule .................................................54 Dawson/Stenerson 3 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 3.3.4 Yearly Rule ..................................................55 3.3.5 Grammar ......................................................56 3.3.6 Grammar Glossary .............................................57 3.3.7 Policies .....................................................58 4. Registration of Content Type Profiles..............................59 4.1 Define the profile ..............................................59 4.2 Post the profile definition .....................................60 4.3 Allow a comment period ..........................................60 4.4 Submit the profile for approval .................................60 4.5 Profile Change Control ..........................................60 4.6 Registration of New Content Type Properties .....................61 4.6.1 Define the property ..........................................61 4.6.2 Post the Property definition .................................62 4.6.3 Allow a comment period .......................................62 4.6.4 Submit the property for approval .............................62 4.7 Content Type Property Change Control ............................62 5. File extension.....................................................63 6. Macintosh File Type Code...........................................63 7. Bibliography.......................................................63 8. Acknowledgments....................................................64 9. Author's Address...................................................64 10. Examples..........................................................65 1. Introduction The use of calendaring and scheduling has grown considerably in the last decade. Enterprise and inter-enterprise business has become dependent on rapid scheduling of events and actions using this information technology. However, the longer term growth of calendaring and scheduling, is currently limited by the lack of Internet standards for the message content types that are central to these groupware applications. This specification is intended to progress the level of interoperability possible between dissimilar calendaring and scheduling applications. This specification defines a MIME content type for exchanging electronic calendaring and scheduling information. The Internet Calendaring and Scheduling Core Object Specification, or iCalendar Object, allows for the capture and exchange of information normally stored within a calendaring and scheduling application; such as a Personal Information Manager or a Group Scheduling product. The format is suitable as an exchange format between applications or systems. The format is defined in terms of a MIME content type. This will enable the object to be exchanged using several transports, including but not limited to SMTP, HTTP, a file system, desktop interactive protocols such as the use of a memory-based clipboard or drag/drop interactions, point-to-point asynchronous communication, wired-network transport, or some form of unwired transport such as infrared might also be used. The specification also provides for the definition of usage profiles that will map this content type to a set of messages for supporting calendaring and scheduling operations such as requesting, replying to, modifying, and canceling meetings or appointments and to-dos. The Dawson/Stenerson 4 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 usage profiles can be used to define other calendaring and scheduling operations such a requesting for and replying with free/busy time data. The specification also includes a formal grammar for the content type to aid in the implementation of parsers and to serve as the definitive reference when ambiguities or questions arise in interpreting the descriptive prose definition of the specification. 1.1 Definitions Date and time terminology is used in every day conversations. However, there are precise definitions of many of these terms that are used by this memo. 1.1.1 Calendar Scale The particular type of calendar in general use. For example, Gregorian, Buddhist Era, Japanese Emperor Era, Chinese Lunar, Islamic, and Jewish Calendars. 1.1.2 Coordinate Universal Time (UTC) The time scale maintained by the Bureau International de l'Heure (International Time Bureau) that forms the basis of a coordinated dissemination of standard frequencies and time signals. UTC is often incorrectly referred to as GMT. 1.1.3 Daylight Saving Time (DST) An adjustment to local to accommodate annual changes in the number of daylight hours. DST is also known as Advanced Time, Summer Time, or Legal Time. Daylight saving time adjustments in the southern hemisphere are opposite to those in the northern hemisphere. 1.1.4 Gregorian Calendar A calendar scale in general use beginning in 1582. It was introduced to correct an error in the Julian Calendar scale. The Gregorian Calendar scale is based on a solar calendar consisting of common years made up of 365 days and leap years made up of 366 days; both divided into 12 sequential months. Initially, this memo addresses specification of calendar information in terms of the Gregorian calendar scale. 1.1.5 Local Time The clock time in public use in a locale. Local time is often referenced by the customary name for the time zone in which it is located. The relationship between local time and UTC is based on the offset(s) that are in use for a particular time zone. In general, the formula is as follows: Dawson/Stenerson 5 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 local time = UTC + (offset) 1.1.6 Standard Time Introduced by Sir Sanford Fleming and others around 1870, standard time is a scheme for dividing the world into zones where the same time would be kept. The original proposal was to divide the world into 24 zones, each zone having a width of 15 degrees of longitude. The center zone was originally the meridian passing through Greenwich, England, called Greenwich Mean Time (GMT). The time in the zones was decremented by one hour per zone going westwards and was incremented by one hour per zone going eastwards from GMT. Changes have been made to the original proposal to accommodate political boundaries. In addition, some countries and regions specify 30 or 45 minute offsets, rather than the full 60 minute offset. Standard time is also known as Winter Time in some regions. GMT and UTC are generally equivalent. However, by international agreement, the GMT term is discouraged in favor of the term UTC for all general time keeping. 1.1.7 Time Zone The particular time zone that a location's time is expressed in. A time zone is unambiguously defined by the set of time measurement rules determined by the governing body for the given location. These rules describe at a minimum the base offset from UTC, often referred to as the Standard Time offset. Optionally, if Daylight time is observed, the rules will specify the Daylight time offset and either a set of rules describing the transition to and from Daylight time or absolute dates describing the movement in and out of Daylight time. It is important to note that these rules are not static. Time zones may also have a local customary name. However, not all time zones have a special name for their time. The customary names for time zones are often abbreviated. However, not all time zone abbreviations are unique. For example, AST may mean Atlantic Standard Time, Alaska Standard Time, and event Aleutian Standard Time. Each of these are different offsets from UTC. Nevertheless, customary names for time zones are in use in various parts of the world. 2. TEXT/CALENDAR Registration Information [Editor NOTE: This form will be changed to reflect the revision to the MIME memos when the respective RFC becomes available.] To: ietf-types@uninett.no Subject: Registration of MIME content type text/calendar. MIME media type name: text MIME subtype name: calendar Required parameters: PROFILE Dawson/Stenerson 6 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 Optional parameters: CHARSET Additional required content header fields: CONTENT-ID, MESSAGE-ID Optional content header fields: CONTENT-LANGUAGE, TRANSFER-ENCODING Encoding considerations: This MIME content type does not introduce any new encoding considerations beyond those defined in [RFC 2045]. Security considerations: The calendaring and scheduling information based on this MIME content type may include references to Uniform Resource Locators that may be programmed resources. In addition, this information may contain direct references to executable programs intended to be used as program-based alarms for an event or to-do. Implementers and users of this specification should be aware of the network security implications of accepting and parsing such information. Interoperability considerations: This MIME content type is intended to provide interoperability between calendaring and scheduling products. It is heavily based on the earlier [VCAL] industry specification. Intended Usage: COMMON Published specification: This document. Person & email address to contact for further information: Frank Dawson 6544 Battleford Drive Raleigh, NC 27613-3502 919-676-9515 (Telephone) 919-676-9564 (Facsimile) fdawson@earthlink.net (Internet Mail) Derik Stenerson One Microsoft Way Redmond, WA 98052-6399 206-936-5522 (Telephone) 206-936-7329 (Facsimile) deriks@microsoft.com (Internet Mail) 3. Intended Use [Editor NOTE: The reference to [RFC 1521] and [MIME-REG] will be changed to reflect the revision to the MIME memos when the respective RFC becomes available.] This memo is meant to serve as the basis for registration of a MIME content type per [RFC1521]. It is defined using the MIME content type registration from [MIME-REG]. The proposed content type value is "TEXT/CALENDAR". This string would label a media type containing Dawson/Stenerson 7 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 calendaring and scheduling information encoded primarily as text characters formatted in a manner outlined below. The media type is useful for conveying inter-personal calendaring and scheduling information between systems and applications. A subtype of the standard MIME _TEXT_ media type was chosen as the form for this content type because it provides a known and reasonable fallback for legacy systems that are required in an enterprise that also includes MIME based user agents that support this content type. Legacy systems that do not understand the _TEXT/CALENDAR_ content type will render these MIME entities as they would _TEXT/PLAIN_ content type. This will provide a minimal level of support for calendaring and scheduling information in legacy systems (i.e., the ability to display the text tagged calendaring and scheduling content information). This is a vital requirement for any mail enabled, enterprise application; as there are still over 7 million existing legacy electronic mail user agents at this time. The calendaring and scheduling media type is specified as an independent content type in order that it can be conveyed either as a single MIME message entity or as one MIME entity in a multi-part MIME message. Additionally, the calendaring and scheduling information may be defined in a multi-part message containing references to other MIME body parts holding additional data related to the event, to-do, or free/busy time information. 3.1 Published specification The following characteristics are specific to this MIME content type. 3.1.1 Existing Message Header Fields The MIME Calendar Content Type may utilize any of the message header fields defined by [RFC 822], [RFC 2045], and [RFC 1766]. A number of these message header fields are especially useful to the iCalendar Object. These include the following header fields defined in either [RFC 822], [RFC 2045], and [RFC 1766]. 3.1.1.1 Content-Type Header Field The [RFC 2045] Content-Type header field is used to identify the iCalendar Object. The value of this property must be _text/calendar_ in order to correspond to the media type defined by this document. This header field is required for MIME entities conforming to this content type. 3.1.1.1.1 CHARSET Header Field Parameter The [RFC 2045] CHARSET Content-Type header field parameter is used to identify an alternate character set to the default US-ASCII used by the iCalendar Object. This header field parameter is optional for MIME entities conforming to this content type. Dawson/Stenerson 8 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 3.1.1.2 Content-ID Header Field The [RFC 2045] Content-ID header field is used by the iCalendar Object to provide a persistent, globally unique identifier for a MIME Calendar Object within a MIME message entity. This header field is required for multi-part MIME entities containing an iCalendar Object that conforms to this content type. In the event that the iCalendar Object is transported in a MIME message containing a single body, then the Message-ID header field is required. 3.1.1.3 Content-Language The [RFC 1766] Content-Language header field is used to provide an alternate default language for the MIME Calendar Object. The default language is _en-US_. This header field is optional for MIME entities conforming to this content type. 3.1.1.4 Message-ID Header Field The [RFC 2045] Message-ID header field is used by the iCalendar Object to provide a persistent, globally unique identifier for a MIME message containing a single body part consisting of a iCalendar Object. This header field is required for a single body part MIME message conforming to this content type. In the event that the iCalendar Object is transported as a body part within a multi-part MIME message, the Content-ID header field must be specified. The Message-ID header field is used to unambiguously refer to the iCalendar Object within a MIME entity. 3.1.1.5 Transfer-Encoding Header Field The [RFC 2045] Transfer-Encoding header field is used to provide an alternate transfer encoding for the iCalendar Object. The default transfer encoding is _7BIT_. This header field is required for a MIME entity conforming to this content type when any other encoding is used in the iCalendar Object. 3.1.2 Additional Content Type Parameter In addition to the existing content type parameters defined by [RFC 2045] and [RFC 1766], this document defines an additional content type parameter to be used by the iCalendar Object. 3.1.2.1 Profile The MIME Calendar Object defines the Profile content type parameter. This parameter is used to specify a usage profile for the iCalendar Object. The value of this parameter consists of a type and a subtype value pair. The type value is used to specify either a EVENT, TODO, or FREE-BUSY type of MIME Calendar Object profile. The subtype value is used to specify the scheduling operation being conveyed by the profile type. For example, the EVENT and TODO type values might have a subtype value of REQUEST, to convey an event or to-do request message, REPLY, to convey an event or to-do reply message, MODIFY, to Dawson/Stenerson 9 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 convey an event or to-do modification message, CANCEL, to convey an event or to-do cancellation message, DELEGATE, to convey an event or to-do delegation message; or the BUSYFREE type value might have a subtype value of REQUEST, to convey a free-busy time request message , or REPLY, to convey a free-busy time data message. The parameter value is defined by the following BNF: profile := ((_EVENT_ / _ _) TODO _-_ type1) / (_FREEBUSY_ _-_ type2) type1 := type2 := The following is an example of this content type parameter for a profile that specifies an event request message, such as in a request for a meeting or appointment: CONTENT-TYPE:TEXT/CALENDAR;PROFILE=EVENT-REQUEST The following is an example of this content type parameter for a profile that specifies a to-do delegation message, such as delegating a task to another individual: CONTENT-TYPE:TEXT/CALENDAR;PROFILE=TODO-DELEGATE The following is an example of this content type parameter for a profile that specifies a free-busy time request, such as when searching for a free time for a meeting: CONTENT-TYPE:TEXT/CALENDAR;PROFILE=FREEBUSY-REQUEST This content type parameter is required for MIME entities conforming to this content type. Other memos are expected to address specific usage profiles and define values for this property. 3.1.3 Content Syntax Considerations The following general considerations are specific to the syntax used to format the text of the body information for this content type. 3.1.3.1 Property A property is the definition of an individual attribute describing an event or a to-do associated with the MIME Calendar Object. A property takes the following form: property := propname *(_;_ propparm) _:_ propvalue as shown in the following example: DTSTART:19960415T083000-05:00 Dawson/Stenerson 10 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 A property takes the form of one or more lines of text. The specification of property names and property parameters is case insensitive. The property name can be one of a set of pre-defined or non-standard strings. The property name must appear as the first characters on a line. In the previous example, _DTSTART_ is the name of the Start Date/Time property. Property values are specified as strings. In the previous example, _19960415T083000-05:00_ is the formatted value for the Start Date/Time property. The property parameter expressions are specified as either a name=value or a value string. The parameter value string can be specified alone in those cases where the value is unambiguous. For example a complete property parameter specification might be: DESCRIPTION;ENCODING=QUOTED-PRINTABLE:Don't forget to order Girl= Scout cookies from Stacey today! A valid short version of the same property parameter specification might be: DESCRIPTION;QUOTED-PRINTABLE:Don't forget to order Girl= Scout cookies from Stacey today! 3.1.3.2 Delimiters Individual lines within the iCalendar Object body are delimited by the [RFC 822] line break, which is a CRLF sequence (ASCII decimal 13, followed by ASCII decimal 10). Long lines of text can be split into a multiple-line representation using the RFC 822 _folding_ technique. That is, wherever there may be linear white space (NOT simply LWSP- chars), a CRLF immediately followed by at least one LWSP-char may instead be inserted. For example the line: DESCRIPTION:This is a long description that exists on a long line. Can be represented as: DESCRIPTION:This is a long description that exists on a long line. The process of moving from this folded multiple-line representation of a property definition to its single line representation is called _unfolding_. Unfolding is accomplished by regarding CRLF immediately followed by a LWSP-char as equivalent to the LWSP-char. It is recommended that folding be limited to higher-level syntactic breaks in structured components of the property definition. A formatted text line break in a property value, must also be specified by a (RFC 822) line break, which is a CRLF sequence. However, since the CRLF sequence is used to delimit a line, property values with formatted line breaks (i.e., multiple lines) must be encoded using an alternate encoding of either Quoted-Printable or Base64, as defined in [RFC 2045]. Dawson/Stenerson 11 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 For example, in the Quoted-Printable encoding the multiple lines of formatted text are separated with a Quoted-Printable CRLF sequence of _=0D_ followed by _=0A_ followed by a Quoted-Printable soft line break sequence of _=_. Quoted-Printable lines of text must also be limited to less than 76 characters. The 76 characters does not include the CRLF [RFC 822] line break sequence. For example a multiple line DESCRIPTION value of: Project XYZ Final Review Conference Room - 3B Come Prepared. Would be represented in a Quoted-Printable encoding as: DESCRIPTION; QUOTED-PRINTABLE:Project XYZ Final Review=0D=0A= Conference Room - 3B=0D=0A= Come Prepared. Property parameter sub-strings are delimited by a field delimiter, specified by the Semi-colon character (ASCII decimal 59). A Semi- colon character in a property parameter value must be escaped with a Backslash character (ASCII decimal 92). Compound property values are delimited by a field delimiter, specified by the Semi-colon character (ASCII decimal 59). A Semi- colon character in a component of a compound property value must be escaped with a Backslash character (ASCII decimal 92). 3.1.3.3 Property Value Transfer Encoding The default transfer encoding for the iCalendar Object is _7BIT_. The default transfer encoding can be overridden for an individual property value by using the _ENCODING_ property parameter. This parameter value can be either _7BIT_, _BASE64_, _QUOTED-PRINTABLE_, or _8BIT_. This parameter may be used on any property. The MIME TRANSFER-ENCODING header field can be used to specify a default transfer encoding other than 7BIT (e.g., 8BIT). 3.1.3.4 Property Value Character Set The default character set for a iCalendar Object is ASCII. The default character set can be overridden for an individual property value by using the _CHARSET_ property parameter. This property parameter may be used on any property. However, the use of this parameter on some properties may not make sense. Any character set registered with the Internet Assigned Numbers Authority (IANA) can be specified by this property parameter. For example, ISO 8859-8 or the Latin/Hebrew character set is specified by: DESCRIPTION;CHARSET=ISO-8859-8:... Dawson/Stenerson 12 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 The MIME CHARSET parameter on the CONTENT-TYPE header field can be used to specify a default character set other than ASCII (e.g., UTF- 8). 3.1.3.5 Property Value Language The default language for a iCalendar Object is _en-US_ (US English). The default language can be overridden for an individual property value by using the _LANGUAGE_ property parameter. The values for this property are a string consistent with RFC 1766, Tags for the Identification of Languages. This property parameter may be used on any property. However, the use of this parameter on some properties, such as PHOTO, LOGO, SOUND, TEL, may not make sense. Canadian French would be specified by this property parameter by the following: SUMMARY;LANGUAGE=fr-CA:... The MIME LANGUAGE parameter on the CONTENT-TYPE header field can be used to specify a default language other than US English (e.g., fr- CA). 3.1.3.6 Property Value Data Type In order to more fully specify the semantics of this content type and to facilitate its automated processing, the specification of each property defined by the iCalendar Object identifies the valid data types and the default data type for the property value. In addition, within an instance of this content type a property may explicitly convey the data type information through the DATATYPE property parameter. The STRING data type for the DESCRIPTION property would be specified by the following: DESCRIPTION;DATATYPE=STRING:Weekly Staff Meeting If the DATATYPE property parameter is not specified on a property, then the default data type for that property is assumed. Usage profiles for this content type that introduce new properties must specify the default data type for each newly defined property. The data types used within this content type definition include the following: Property Data Description Type AALARM Indicates an audio alarm value, as specified by this document. Dawson/Stenerson 13 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 BOOLEAN Indicates a Boolean value string of either TRUE or FALSE. CID Indicates a string identifier value for the content identifier of another MIME entity within the current message. DALARM Indicates a display alarm value, as specified by this document. DATE-TIME Indicates an ISO 8601 formatted date/time string value. DST-RULE Indicates a daylight saving time rule value as specified in this document. D-T-LIST Indicates a list of ISO 8601 formatted date/time string values. DURATION Indicates an ISO 8601 formatted duration or period of time value. Dawson/Stenerson 14 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 FLOAT Indicates a string representatio n of a floating point value. FLOAT-LIST Indicates a list of string representatio ns of floating point values. INTEGER Indicates a numeric string representatio n of an integer value. INTEGER-LIST Indicates a list of numeric string representatio ns of an integer value. MALARM Indicates a mail alarm value, as specified by this document. MID Indicates a string identifier value for an external message. PALARM Indicates a procedure alarm value, as specified by this document. Dawson/Stenerson 15 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 RFC822- Indicates a ADDRESS RFC 822 formatted address specification string value. RRULE Indicates a recurrence rule grammar string value as specified in this document. STRING Indicates a text string value in the current character set. STRING-LIST Indicates a list of text string values in the current character set. TIME-OFFSET Indicates an ISO 8601 formatted time offset value URL Indicates a RFC 1738 formatted Uniform Resource Locator string. The property values consisting of lists of a particular data type (i.e., STRING-LIST) are semi-colon separated string of list items. 3.1.3.7 Date and Time The date and time values for all iCalendar Object properties are formatted as a string consistent with the ISO 8601 representation for Dawson/Stenerson 16 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 combinations of dates and times. Either the basic or extended format is allowed. The use of UTC, rather than local time, should be used when ever possible in order to avoid time zone ambiguities. Where local time is specified, the inclusion of the UTC offset should also be included to avoid time zone ambiguities. The format for the complete, representation of a date and time value is represented by the following ABNF: date-time = (date / time / (date _T_ time)) date = year month day year = month = [_-_] day = [_-_] time = hour minute second [fraction](utc-sign / utc-offset) hour = minute = [_:_] second = [_:_] fraction = _,_ utc-sign = _Z_ utc-offset = [_+_ / _-_] hour [_:_] minute ;_+_ if offset is after UTC and _-_ if offset is before UTC The basic complete representation does not include the _-_ date separator nor the _:_ time separator. The extended complete representation does include the separators. For example, 8:30 AM on April 15, 1996 local time EST would be written as: 19960415T083000-05:00 And the same time in UTC based time would be written as: 19960415T133000Z The same date and time represented in the extended completed representation would be written as: 1996-04-15T08:30:00-05:00 And the same time in UTC based time would be written as: 1996-04-15T13:30:00Z Where a value needs to specify a sequence of date and time values, then the property value is a string made up of a list of date and time values, separated by the field separator, a Semi-Colon (ASCII decimal 59). For example: Dawson/Stenerson 17 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 19960101T090000Z;19960201T090000Z;19960301T090000Z;... 3.1.3.8 Time Duration The values for time duration or periods of time for all iCalendar Object properties are formatted as a string consistent with the ISO 8601 representation for duration of time. A given duration of a period of time is represented by a character string consisting of the designator _P_, optionally including the number of years followed by the designator _Y_, optionally including the number of months followed by the designator _M_, optionally including the number of weeks followed by the designator _W_, optionally including the number of days followed by the designator _D_. The sequence can also contain a time component preceded by the designator _T_, optionally including the number of hours followed by the designator _H_, optionally including the number of minutes followed by the designator _M_, optionally including the number of seconds followed by the designator _S_. The following ABNF describes the representation of ISO 8601 periods of time: duration = _P_ (yr-period / tm-period / (yr-period tm-period)) ;Duration needs to include at least one component of year or ;time periods yr-period = [yr-parm] [mo-parm] / wk-parm yr-parm = _Y_ mo-parm = _M_ wk-parm = _W_ tm-period = _T_ [hr-parm] [mn-parm] [sc-parm] hr-parm = _H_ mn-parm = _M_ sc-parm = _S_ For example: P6W represents a period of six weeks; PT15M represents a period of 15 minutes; PT1H30M represents a period of 1 hour and thirty minutes; or P2Y10M15DT10H30M20S represents a period of 2 years, 10 months, 15 days, 10 hours, 30 minutes, and 20 seconds. Dawson/Stenerson 18 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 3.1.3.9 Value Location The default location of the property values is inline with the property. However, for some properties, such as those that specify multimedia values, it is more efficient in a MIME message to organize the property value as a separate MIME entity. The property parameter _VALUE_ can be specified to override the _INLINE_ location of the property value. In the case of the iCalendar Object being transported within a MIME email message, the property value can be specified as being located in a separate MIME entity with the _CONTENT-ID_ value; or _CID_ for shorthand. In this case, the property value is the Content-ID for the MIME entity within the multi-part message that contains the property value. The value can also be specified as being contained within an another, external message using the _MESSAGE-ID_ value, or _MID_ for shorthand. In addition, the property value can be specified as being located out on the Internet using the _URL_ value. In this case, the property value is the Uniform Resource Locator for the Internet resource containing the property value. This property parameter may be used on any property. However, the use of this parameter on some properties may not make sense; for example the Version, Time Zone, Status, Priority, Mail Reminder, etc. properties. The following specifies a value located out on the Internet: ATTACH;VALUE=URL:http://www.abc.com/dir_photos/my_photo.gif The following specifies a value located out in the content of another message: ATTACH;VALUE=MID:<960120.aaCB@host1.com> 3.1.3.10 Binary Property Values The iCalendar Object supports inclusion of binary information, such as computer graphic images (e.g., IMAGE/JPEG), digital audio (e.g., AUDIO/BASIC), or video graphic images (e.g., VIDEO/MPEG). As specified above the binary information can be referenced with a Uniform Reference Locator (URL), referenced within an external MIME message, referenced within a particular MIME message body part, or placed inline. Inline binary information is included as a property value after being binary encoded using Base 64 (default) or Quoted- Printable transfer encoding. 3.1.3.11 Recurrence Rule Grammar Recurring events within the iCalendar Object may be specified as either a list of discrete date and time values or as a recurrence rule using a grammar. The basic recurrence rule grammar used by this specification is defined in a separate section of this specification. The grammar defines a recurrence rule that that is based on the prior work of the X.400 API Association's Calendaring and Scheduling Subcommittee. It is also based on prior work of the IETF Chronos Working Group. Refer to section 3.3. Dawson/Stenerson 19 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 3.1.4 Body Delimiter Properties The body information of a iCalendar Object is defined by a series of body fields or properties. This section defines the properties that can be used in MIME entities conforming to this content type. 3.1.4.1 Calendar Object The body of the iCalendar Object is identified within the body of a MIME entity by the appearance of the Begin Calendar Object Delimiter: BEGIN:VCALENDAR The sentinel string must appear as the first characters in the body of the MIME entity and as the first characters on a line. The body information of the iCalendar Object is terminated by the appearance of the End Calendar Object Delimiter as the first characters on a line: END:VCALENDAR The iCalendar Object is a container for calendar components. These can include either event or to-do components. The body of a iCalendar Object will generally contain a single calendar event or to-do component. However, the body may include multiple event or to-do components. This is the case for free-busy time reply messages that contain multiple free time intervals in individual calendar components. The Begin and End Calendar Object Delimiter properties are required in a MIME entity conforming to this content type. The data type for these properties is a STRING. 3.1.4.2 Event Component An Event Component is a grouping of calendaring and scheduling properties that defines a component that represents a scheduled amount of time on a calendar. For example, it may be an activity; such as a one-hour, department meeting from 8 AM to 9 AM, tomorrow or a free/busy time interval. An individual Event Component is identified within a MIME Calendaring and Scheduling Content Type by the appearance of the delimiter: BEGIN:VEVENT The sentinel string must appear as the first characters on a line. The Event Component is terminated with the appearance of the following delimiter string as the first characters on a line END:VEVENT Dawson/Stenerson 20 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 The Event Component can not be nested within another Event or To-do Component. If Event components need to be related to each other or to a To-do Component, they can specify a relationship with the RELATED- TO property. The Begin and End Event Component Delimiter properties are required for a MIME entity containing an event component and conforming to this content type. The data type for these properties is a STRING. 3.1.4.3 To-do Component A To-do Component is a grouping of calendaring and scheduling properties that define a component that represents an action-item or assignment. For example, it may be an item of work assigned to an individual; such as _turn in travel expense today_. An individual To-do Component is identified within a MIME Calendaring and Scheduling Content Type by the appearance of the delimiter: BEGIN:VTODO The sentinel string must appear as the first characters on a line. The To-do Component is terminated with the appearance of the following delimiter string as the first characters on a line END:VTODO The To-do Component can not be nested within another To-do or Event Component. If To-do components need to be related to each other or to an Event Component, they can specify a relationship with the RELATED- TO property. The Begin and End To-do Component Delimiter properties are required for a MIME entity containing a to-do component and conforming to this content type. The data type for these properties is a STRING. 3.1.5 Calendar Object Properties The following properties may appear between the Begin Calendar Object Delimiter and either the Begin Event Component Delimiter or the Begin To-do Component Delimiter. These properties define body field values that apply to the complete calendar object. 3.1.5.1 Calendar Content Profile This property is identified by the property name PROFILE. This property defines the usage profile associated with the calendar object. When used in a MIME message entity, the value of this property MUST be the same as the Content-Type profile parameter value. This property can only appear once within the iCalendar Object. Dawson/Stenerson 21 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 The calendar property value might include the following usage profile values: Profile Parameter Description Type/Subtype Value EVENT-REQUEST Make a request for an event EVENT-REPLY Reply to an event request EVENT-COUNTER Make a counter proposal to the event request EVENT-DECLINECOUNTER Decline the counter proposal to the event request EVENT-MODIFY Modify a subset of the details of an existing event request EVENT-REPLACE Replace the current event request with a complete set of information EVENT-CANCEL Cancel an existing event request EVENT-DELEGATE Delegate an existing event request EVENT-RESEND Request a duplicate of the current event request information TODO-REQUEST Assign a to-do Dawson/Stenerson 22 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 TODO-REPLY Reply to a to-do assignment TODO-COUNTER Make a counter proposal for the to-do request TODO-DECLINECOUNTER Decline a counter proposal for the to-do request TODO-MODIFY Modify a subset of the details of an existing to-do assignment TODO-REPLACE Replace the current to- do request with a complete set of information TODO-CANCEL Cancel an existing to- do TODO-DELEGATE Delegate an existing to-do TODO-RESEND Request a duplicate of the current to-do request information FREEBUSY-REQUEST Free/busy time request FREEBUSY-REPLY Reply to an existing free/busy time request with free/busy time data Other values may be defined by other usage profiles of this content type. Dawson/Stenerson 23 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 This property is optional for MIME entities conforming to this content type. In the event that this property is not specified, the recipient of a MIME Calendaring and Scheduling Content Type should assume the calendar object is for an _event/request_. The data type for this property is STRING. 3.1.5.2 Calendar Scale This property is identified by the property name CALENDAR. This property defines the calendar scale used for the calendar information specified in the iCalendar Object. This specification is based on the Gregorian calendar scale. The Gregorian calendar scale is assumed if this property is not specified in the iCalendar Object. It is expected that other calendar scales will be defined in other specifications or by future versions of this specification. The following is an example of this property: CALENDAR:GREGORIAN The data type for this property is STRING. 3.1.5.3 Daylight Savings Rule This property is identified by the property name DAYLIGHT. This property defines the effective daylight savings time rule for calendar information specified in the iCalendar Object. More than one DAYLIGHT properties can be specified for a series of future DST rules for the time zone. Many locations adjust their standard time forward or backward by one hour, in order to accommodate seasonal changes in number of daylight hours. Some locations adjust their time by a fraction of an hour. Standard time is also known as Winter Time. Daylight savings time is also known as Advanced Time, Summer Time, or Legal Time in certain countries. The property value consists of a sequence of components that define a rule for the observance of daylight savings time. The value consists of effective start date for the DST rule, followed by the daylight savings time flag, followed by the daylight savings time offset from UTC, followed by the date and time of the transition from standard time to daylight savings time, followed by the date and time of the transition from daylight savings time to standard time, followed by the customary standard time designation, followed by the customary daylight savings time designation. The effective start date for the DST rule allows for the specification of a series of future DST rules for a given time zone. The daylight savings time flag is TRUE if daylight savings time is observed, otherwise it is FALSE and no other components are specified. The daylight savings time offset value is specified in a manner consistent with ISO 8601. The property value is a signed numeric indicating the number of hours and possibly minutes from UTC. The date and time that the daylight savings time begins and ends is specified in a manner consistent with ISO 8601 date and time Dawson/Stenerson 24 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 format. The standard time and daylight savings time designations correspond to the customary character designations. The following are examples of this property: DAYLIGHT:19960407;TRUE;-06;19960407T025959;19961027T010000;EST;EDT DAYLIGHT:FALSE DAYLIGHT:19960407;TRUE;-09;19960407T115959;19961027T100000;PST;PDT This property is optional for MIME entities conforming to this content type. In the event that this property is not specified, the recipient of a MIME Calendaring and Scheduling Content Type should assume the same daylight savings time rule as the recipient location. The data type for this property is DST-RULE. 3.1.5.4 Geographic Position This property is identified by the property name GEO. This property specifies information related to the global position of the _home_ system that created the MIME calendar object. The property value specifies longitude and latitude. The longitude represents the location east and west of the prime meridian as a positive or negative real number, respectively. The latitude represents the location north and south of the equator as a positive or negative real number, respectively. The following is an example of this property: GEO:37.24,-17.87 This property is optional for MIME entities conforming to this content type. The default data type for this property is FLOAT-LIST. Optionally, the data type for this property may be URL. The URL is the resource location for the geographical position value. 3.1.5.5 Product Identifier This property is identified by the property name PRODID. This property specifies the identifier for the product that created the MIME calendar object. The vendor of the implementation should assure that this is a globally unique identifier; using some technique such as an ISO 9070 FPI value. The following is an example of this property: PRODID:-//ABC Corporation//NONSGML My Product//EN This property is required for MIME entities conforming to this content type. The default data type for this property is STRING. Optionally, the data type may be URL. The URL is the resource location for the product identifier value. Dawson/Stenerson 25 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 3.1.5.6 Time Zone This property is identified by the property name TZ. This property specifies the standard time zone of the _home_ system that created the MIME calendar object. The property value is specified in a manner consistent with ISO 8601. The property value is a signed numeric indicating the number of hours and possibly minutes from UTC. Time zones east of UTC are positive numbers. Time zones west of UTC are negative numbers. The following are examples of this property: TZ:-0500 TZ:+05:30 This property is optional for MIME entities conforming to this content type. If this property is missing, the recipient should assume all local times are relative to the recipients time zone. The data type for this property is TIME-OFFSET. Optionally, the data type for this property may be STRING. 3.1.5.7 Version This property specifies the identifier corresponding to the highest version number of the MIME Calendaring and Scheduling Content Type specification supported by the implementation that created the MIME calendar object. The value of this property must be 2.0 to correspond to this specification.. This property is identified by the property name VERSION. The following is an example of this property: VERSION:2.0 This property is required for MIME entities conforming to this content type. This property must appear within the MIME calendar object. The data type for this property is FLOAT. 3.1.6 Event and To-do Component Properties The following properties apply to either an event or to-do calendar object component. 3.1.6.1 Attachment This property is identified by the property name ATTACH. The property defines an attached object to the MIME calendar object. For example, a document to be reviewed at a scheduled event or the process steps for a to-do. The property value can be a text string, a reference to another message body part or a reference to a URL corresponding to a document. Multiple attachments may be specified by including multiple ATTACH properties within the MIME calendaring entity. Dawson/Stenerson 26 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 The following are examples of this property: ATTACH;VALUE=CONTENT-ID: ATTACH;VALUE=URL:file://xyzCorp.com/pub/reports/r-960812.ps This property is optional for MIME entities conforming to this content type. The default data type for this property is MID. The data type may alternatively be specified to be CID, URL, or STRING value. 3.1.6.2 Attendee This property is identified by the property name ATTENDEE. The property defines an attendee to a group event or to-do. The default property value is an (RFC 822) address. The property may include property parameters TYPE, for the type of attendee, ROLE, for the role of the attendee in the event or to-do; STATUS, for the status of the attendee's participation in the event or to-do, RSVP, for indicating whether the favor of a reply is requested, EXPECT, to indicate the expectation of the attendee's participation by the originator, and MEMBER, to indicate the group that the attendee belongs to. Multiple attendees may be specified by including multiple ATTENDEE properties within the MIME calendaring entity. The property value may reference a vCard object. This provides a useful mechanism to allow more than just the address of the attendee to be referenced. The TYPE property parameter for each attendee can have the following values: Dawson/Stenerson 27 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 Property Description Value INDIVIDUAL Indicates attendee is an individual. GROUP Indicates attendee is a group of individuals. RESOURCE Indicates attendee is a resource. UNKNOWN Indicates attendee type is unknown. The ROLE property parameter for each attendee can have the following values: Property Description Value ATTENDEE Indicates an attendee at the event or to-do ORGANIZER Indicates organizer of the event, but not owner OWNER Indicates owner of the event or to- do. Dawson/Stenerson 28 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 DELEGATE Indicates a delegate of another attendee. The default value for this property parameter is ATTENDEE. The STATUS property parameter for each attendee can have the following values: Property Description Value ACCEPTED Indicates to- do was accepted by attendee NEEDS ACTION Indicates event or to- do requires action by attendee SENT Indicates event or to- do was sent out to attendee TENTATIVE Indicates event is tentatively accepted by attendee CONFIRMED Indicates attendee has confirmed their attendance at the event DECLINED Indicates event or to- Dawson/Stenerson 29 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 do has been rejected by attendee COMPLETED Indicates to- do has been completed by attendee DELEGATED Indicates event or to- do has been delegated by the attendee to another CANCELED Indicates the event or to- do has been canceled and/or this attendee has been removed from the list of attendees. The default value for this property parameter is NEEDS ACTION. The RSVP property parameter for each attendee can have the following values: Property Description Value YES Indicates a reply is requested NO Indicates a reply is not requested. The default value for this property parameter is NO. Dawson/Stenerson 30 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 The EXPECT property parameter for each attendee can have the following values: Property Description Value FYI Indicates request is for your information. REQUIRE Indicates presence is definitely required. REQUEST Indicates presence is being requested IMMEDIATE Indicates an immediate response needed. The default value for this property parameter is FYI. The MEMBER property parameter value is an (RFC 822) address that represents the group or distribution list. The following is an example of this property's use for a to-do: ATTENDEE;ROLE=OWNER;STATUS=COMPLETED:jsmith@host1.com The following is an example of this property used for specifying multiple attendees to an event: ATTENDEE;ROLE=OWNER;STATUS=CONFIRMED:John Smith ATTENDEE;ROLE=ATTENDEE;STATUS=TENTATIVE:Henry Cabot ATTENDEE;ROLE=DELEGATE;STATUS=CONFIRMED:Jane Doe The following is an example of this property with the value specified as an URL reference to a vCard that contains the information about the attendee: Dawson/Stenerson 31 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 ATTENDEE;ROLE=ATTENDEE;STATUS=CONFIRMED;VALUE=URL: http://www.xyz.com/~myvcard.vcf This property is optional for MIME entities conforming to this content type. The default data type for this property is RFC822- ADDRESS. Optionally, the data type for this property may be URL, MID, or CID; in which case the value is a location or message that contains information that is to be used to specify the attendee. 3.1.6.3 Audio Reminder This property is identified by the property name AALARM. The property defines an audio reminder for the MIME calendar object. An audio reminder is an alarm that is sounded for a calendar component.. The value for the audio reminder consists of the Run Time, or the date and time that the reminder is to be executed; Snooze Time, or the duration of time after the Run Time that the reminder is to be dormant prior to being repeated; Repeat Count, or the number of times that the reminder is to be repeated; and the Audio Content, or the digital sound to be played when the reminder is executed. The following are some examples of this property: AALARM;TYPE=WAVE;VALUE=URL:19960415T235959; ; ; file:///mmedia/taps.wav AALARM;TYPE=WAVE;VALUE=CONTENT- ID:19960903T060000;PT15M;4; The property has the following additional property parameters: Property Description Parameter Values TYPE - - Any IANA Indicates a registered MIME audio audio content content type type. value - - WAVE Indicates the WAVE format for audio content. Dawson/Stenerson 32 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 AIFF Indicates the AIFF format for audio content. The Reminder properties are primarily provided as a means for allowing the capture of alarm information when accessing a calendar system. It may not be an appropriate property to send in an event or to-do request. This property is optional for MIME entities conforming to this content type. The default data type for this property is AALARM. Optionally, the data type may be specified to be CID, MID, or URL. 3.1.6.4 Categories This property is identified by the property name CATEGORIES. This property defines the categories for the MIME calendar component. More than one category may be specified as a list of categories separated by the Semi-Colon character (ASCII decimal 59). The following are some examples of this property: CATEGORIES:APPOINTMENT;EDUCATION CATEGORIES:MEETING Some of the possible values for this property might include the following: Some Possible Property Values APPOINTMENT BUSINESS EDUCATION HOLIDAY MEETING MISCELLANEOUS Dawson/Stenerson 33 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 NON-WORKING-HOURS NOT-IN-OFFICE PERSONAL PHONE CALL SICK DAY SPECIAL OCCASION TRAVEL VACATION This property is optional for MIME entities conforming to this content type. The data type for this property is STRING-LIST. 3.1.6.5 Classification This property is identified by the property name CLASS. This property defines the access classification for the MIME calendar component. A calendar event/to-do access classification is only one component of the general security system within a calendar application. It provides a method of capturing the scope of the access the calendar owner intends for information within an individual calendar entry. The access classification of an individual MIME calendaring entity is useful when measured along with the other security components of a calendar system (e.g., user authorization, access rights, access role, etc.). Hence, the semantics of the individual access classifications can not be completely defined by this specification. Additionally, due to the _blind_ nature of most exchange processes using this specification, these entity classifications can not serve as an enforcement statement for a system receiving a MIME calendar object . Rather, they provide a method for capturing the intention of the calendar owner for the access to the MIME calendar object component. The following is an example of this property: CLASS:PUBLIC The property can have the following values: Dawson/Stenerson 34 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 Property Description Value PUBLIC Indicates general, public access. PRIVATE Indicates restricted, private access. CONFIDENTIAL Indicates very restricted, confidential access. The default value for this property is PUBLIC. This property is optional for MIME entities conforming to this content type. The data type for this property is STRING. 3.1.6.6 Date/Time Created This property is identified by the property name DCREATED. This property specifies the date and time that the MIME calendar component was created within the originating calendar system. This is not necessarily the same date and time that the MIME calendar object was created. The date and time value is the local or UTC based time expressed in the complete representation, basic or extended format as specified in ISO 8601. The following is an example of this property: DCREATED:19960329T083000-0500 This property is optional for MIME entities conforming to this content type. The data type for this property is DATE-TIME. 3.1.6.7 Date/Time Completed This property is identified by the property name COMPLETED. This property defines the date and time that the to-do was actually completed. The date and time value is expressed in the complete representation, basic or extended format as specified in ISO 8601. The time can either be in local or UTC based time. The following is an example of this property: Dawson/Stenerson 35 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 COMPLETED:19960401T235959Z This property is optional for MIME entities conforming to this content type. The data type for this property is DATE-TIME. 3.1.6.8 Description This property is identified by the property name DESCRIPTION. This property provides a more complete description of the MIME calendar component, than that provided by the SUMMARY property. The following is an examples of the property with formatted line breaks in the property value: DESCRIPTION;ENCODING=QUOTED-PRINTABLE:Meeting to provide technical= review for _Phoenix_ design.=0D=0A= Happy Face Conference Room. Phoenix design team= must attend this meeting. RSVP to team leader. The following is an examples of the property with folding of long lines: DESCRIPTION:Last draft of the new novel is to be completed for the editor's proof today. This property is required for MIME entities conforming to this content type. The data type for this property is STRING. Optionally, the data type may be URL, MID, or CID. 3.1.6.9 Display Reminder This property is identified by the property name DALARM. The property defines a display reminder for the MIME calendar component. A display reminder is an alarm that is popped up into the user interface or otherwise visually displayed for a calendar component. The value for the display reminder consists of the Run Time, or the date and time that the reminder is to be executed; Snooze Time, or the duration of time after the Run Time that the reminder is to be dormant prior to being repeated; Repeat Count, or the number of times that the reminder is to be repeated; and the Display String, or the text to be displayed when the reminder is executed. The following is an example of this property: DALARM:19960415T235000-0800;PT5M;2;Your Taxes Are Due !!! The Reminder properties are primarily provided as a means for allowing the capture of alarm information when accessing a calendar system. It may not be an appropriate property to send in an event or to-do request. This property is optional for MIME entities conforming to this content type. The default data type for this property is DALARM. Optionally, the data type may be specified to be CID, MID, or URL. Dawson/Stenerson 36 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 3.1.6.10 Due Date/Time This property is identified by the property name DUE. This property defines the date and time that the to-do is due to be completed. The date and time value is expressed in the complete representation, basic or extended format as specified in ISO 8601. The time can either be in local or UTC based time. Alternatively, the value may be a duration of time, expressed in the ISO 8601 format as specified in section 3.1.3.8. In this case, the end is relative to the start of the MIME calendar component. The following is an example of this property: DUE:19960401T235959Z This property is required for MIME entities consisting of a to-do calendar component that conforms to this content type. The default data type for this property is DATE-TIME. Optionally, the data type may be specified as a DURATION. 3.1.6.11 Duration This property is identified by the property name DURATION. The property specifies an interval or duration of time. This property can be used with the DTSTART property to specify a relative duration for an event (e.g., event starts at 8:00 am and lasts for one hour). The property can also be used in constructing a free-busy time request (e.g., find free time periods of 15 minute duration, or longer). The following is an example of this property that specifies an interval of time of 1 hour and zero minutes and zero seconds: DURATION:PT1H0M0S The following is an example of this property that specifies an interval of time of 15 minutes. DURATION:PT15M This property is optional for MIME entities conforming to this content type. The data type for this property is DURATION. 3.1.6.12 End Date/Time This property is identified by the property name DTEND. This property defines the date and time that the event component will end. The date and time value is expressed in the complete representation, basic or extended format as specified in ISO 8601. The time can either be in local or UTC based time. Alternatively, the value may be a duration of time, expressed in the ISO 8601 format as specified in section 3.1.3.8. In this case, the end is relative to the start of the MIME calendar component. Events may have an end date/time but no start date/time. In that case, the event does not take up any time. The following is an example of this property: DTEND:19960401T235959Z Dawson/Stenerson 37 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 This property is required for MIME entities conforming to this content type. The default data type for this property is DATE-TIME. The data type may alternatively be specified as a DURATION. 3.1.6.13 Exception Date/Times This property is identified by the property name EXDATE. This property defines the list of date/time exceptions for a recurring MIME calendar component. The date and time values is expressed in the complete representation, basic format as specified in ISO 8601. The times can either be in local or UTC based time. The following is an example of this property: EXDATE:19960402T010000Z;19960403T010000Z;19960404T010000Z This property is optional for MIME entities conforming to this content type. The data type for this property is D-T-LIST. Optionally, the data type may be URL; in which case the value is the location where a list of exception dates can be found. This latter case is a useful method for conveying dynamic exceptions dates, such as holidays, for a recurring event or to-do. 3.1.6.14 Exception Rule This property is identified by the property name EXRULE. This property defines a rule or repeating pattern for an exception to a recurring MIME calendaring entity, based on the Basic Recurrence Rule Grammar of the [XAPIA]. The value for the property is a pattern specification for the recurrence exception. The following are some examples of this property: EXRULE:W2 TU TH #2 // Except every other week, on Tuesday // and Thursday for 4 occurrences EXRULE:D1 #10 // Except daily for 10 occurrences EXRULE:YM1 6 7 #8 // Except yearly in June and July for 8 // occurrences This property is optional for MIME entities conforming to this content type. The data type for this property is RRULE. 3.1.6.15 Last Modified This property is identified by the property name LAST-MODIFIED. The property specifies the date and time that the MIME calendar component was last revised. The following is an example of this property: LAST-MODIFIED:19960817T133000Z This property is optional for MIME entities conforming to this content type. The data type for this property is DATE-TIME. Dawson/Stenerson 38 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 3.1.6.16 Location This property is identified by the property name LOCATION. The property defines the intended location for the MIME calendar component. The property value may reference a vCard object. This provides a useful mechanism to specify a location in terms of its electronic business card. The following are some examples of this property: LOCATION:Conference Room - F123, Bldg. 002 // or LOCATION;VALUE=URL:http://www.xyzcorp.com/~jsmith.vcf This property is optional for MIME entities conforming to this content type. The default data type for this property is STRING. Optionally the data type may URL, MID, or CID. 3.1.6.17 Mail Reminder This property is identified by the property name MALARM. The property defines an email address that is to be sent a reminder for the MIME calendar component. A mail reminder is an electronic mail address that will be sent a display string as an alarm for a calendar component. The value for the procedure reminder consists of the Run Time, or the date and time that the reminder is to be executed; Snooze Time, or the duration of time after the Run Time that the reminder is to be dormant prior to being repeated; Repeat Count, or the number of times that the reminder is to be repeated; Email Address, or the (RFC 822) email address that is to be sent the reminder, Subject, or the textual subject of the note, and the Note, or the textual reminder string that is to be sent to the email address. The following is an example of this property: MALARM:19960416T000000-0500;PT1H;24;IRS@us.gov;My Payment; The Check Is In The Mail! The Reminder properties are primarily provided as a means for allowing the capture of alarm information when accessing a calendar system. It may not be an appropriate property to send in an event or to-do request. This property is optional for MIME entities conforming to this content type. The default data type for this property is MALARM. Optionally, the data type may be URL, MID, or CID. Dawson/Stenerson 39 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 3.1.6.18 Number Recurrences This property is identified by the property name RNUM. The property defines the number of times the calendar entry will reoccur. The value is equal to the number of recurrences that are specified by the union of the Recurrence Dates, Recurrence Rule, Exception Dates, and Exception Rule property values. The following is an example of this property: RNUM:3 In the event that this value does not match the computed number of recurrences, it will be ignored and the computed number of recurrences will be used. This property is optional for MIME entities conforming to this content type. The data type for this property is INTEGER. 3.1.6.19 Priority This property is identified by the property name PRIORITY. The property defines the priority for the MIME calendar component. The value is an alphanumeric. A value of zero (ASCII decimal 48) specifies an undefined priority. A value of one (ASCII decimal 49) is the highest priority. A value of two (ASCII decimal 50) is the second highest priority. Subsequent numbers specify a decreasing ordinal priority. The following is an example of this property: PRIORITY:2 This property is optional for MIME entities conforming to this content type. The default data type for this property is STRING. Optionally the data type may be specified to be INTEGER. 3.1.6.20 Procedure Reminder This property is identified by the property name PALARM. The property defines a procedure reminder for the MIME calendar component. A procedure reminder is a procedure, or application executable that will be run as an alarm for a calendar component. While this property has many useful purposes, implementers should be aware of the security implications of sending a MIME calendaring entity containing this property. The security implications are similar to those associated with active messages within electronic mail. The value for the procedure reminder consists of the Run Time, or the date and time that the reminder is to be executed; Snooze Time, or the duration of time after the Run Time that the reminder is to be dormant prior to being repeated; Repeat Count, or the number of times that the reminder is to be repeated; and the Procedure Name, or the path to the procedure to be run when the reminder is executed. Parameters are passed to the procedure by concatenating to the Dawson/Stenerson 40 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 Procedure Name value a Question-Mark (ASCII decimal 63) followed by a string representation of the parameters. The following is an example of this property: PALARM;VALUE=URL:19960415T235000-0500;PT5M;2;file:///myapps/ shockme.exe?HARD The Reminder properties are primarily provided as a means for allowing the capture of alarm information when accessing a calendar system. It may not be an appropriate property to send in an event or to-do request. This property is optional for MIME entities conforming to this content type. The default data type for this property is PALARM. Optionally, the data type may be URL, MID, or CID. 3.1.6.21 Related To This property is identified by the property name RELATED-TO. The property is used to represent relationships or references between this MIME calendar component and another. The property value consists of the persistent, globally unique identifier of another MIME calendar component. This value would be represented in a MIME calendar component by the UID property. A linked relationship can be specified by a series of components that each, in turn, refer to their parent component. A group relationship can be specified by a number of components that all refer to one common parent component. Changes to a calendar component referenced by this property may impact the related calendar component. For example, if a group event changes its start or end date or time, then the related, dependent events will need to have their start and end dates changed in a corresponding way. This property is intended only to provide information on the relationship of calendar components. It is up to the target calendar system to maintain this relationship. The following is an example of this property: RELATED-TO: RELATED-TO:19960401-080045-4000F192713-0052 This property is optional for MIME entities conforming to this content type. The default data type for this property is STRING. Optionally, the data type may be URL, MID, or CID. 3.1.6.22 Recurrence Date/Times This property is identified by the property name RDATE. This property defines the list of date/times for a recurring MIME calendar component. This property may appear along with the RRULE property to Dawson/Stenerson 41 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 define an aggregate set of repeating occurrences. When they both appear in an iCalendar Object, the recurring events are defined by the union of occurrences defined by both the RDATE and RRULE. The date and time values is expressed in the complete representation, basic format as specified in ISO 8601. The times can either be in local or UTC based time. The number of recurring date/times is specified by the Number Recurrences property. The following is an example of this property: RDATE:19960402T010000Z;19960403T010000Z;19960404T010000Z This property is optional for MIME entities conforming to this content type. The default data type for this property is D-T-LIST. Optionally, the data type may be URL; in which case the value is the location where a list of recurring dates can be found. This latter case is a useful method for conveying dynamic recurring dates, such as schedules, for a recurring event or to-do. 3.1.6.23 Recurrence Rule This property is identified by the property name RRULE. This property defines a rule or repeating pattern for a recurring MIME calendar component, based on the Basic Recurrence Rule Grammar of [XAPIA]. The value for the property is a pattern specification for the recurrence. This property may appear along with the RDATE property to define an aggregate set of repeating occurrences. When they both appear in an iCalendar Object, the recurring events are defined by the union of occurrences defined by both the RDATE and RRULE. The following are examples of this property: RRULE:W2 TU TH // Every other week, on Tuesday // and Thursday RRULE:D1 #10 // Daily for 10 occurrences RRULE:YM1 6 7 #8 // Yearly in June and July for 8 // occurrences This property is optional for MIME entities conforming to this content type. The data type for this property is RRULE. 3.1.6.24 Resources This property is identified by the property name RESOURCES. This property defines the equipment or resources needed in the MIME calendar component. Some of the values that the property may have include the following: Some Possible Dawson/Stenerson 42 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 Property Values CATERING CHAIRS COMPUTER PROJECTOR EASEL OVERHEAD PROJECTOR SPEAKER PHONE TABLE TV VCR VIDEO PHONE VEHICLE The following is an example of this property: RESOURCES:EASEL;PROJECTOR;VCR This property is optional for MIME entities conforming to this content type. The default data type for this property is STRING-LIST. The data type may alternatively be specified to be STRING. 3.1.6.25 Response Sequence Number This property is identified by the property name RESPONSE-SEQUENCE. This property defines the instance of the MIME calendar component in a revision sequence of responses. This property is needed to properly handle the receipt and processing of a sequence of MIME calendar components that have been delivered out of order. Such is the case for store-and-forward based transports. When a response to an original MIME calendaring entity is created its sequence number is zero (ASCII decimal 48). It is incremented each time it is revised. The following is an example of this property: RESPONSE-SEQUENCE:1 This property is optional for MIME entities conforming to this content type. The data type for this property is INTEGER. Dawson/Stenerson 43 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 3.1.6.26 Sequence Number This property is identified by the property name SEQUENCE. This property defines the instance of the MIME calendar component in a sequence of revisions. This property is needed to properly handle the receipt and processing of a sequence of MIME calendar components that have been delivered out of order. Such is the case for store-and- forward based transports. When a MIME calendaring entity is created its sequence number is zero (ASCII decimal 48). It is incremented each time it is revised by the OWNER and/or ORGANIZER. The following is an example of this property: SEQUENCE:1 This property is optional for MIME entities conforming to this content type. The data type for this property is INTEGER. 3.1.6.27 Start Date/Time This property is identified by the property name DTSTART. This property defines the date and time that the calendar component will start. The date and time value is expressed in the complete representation, basic format as specified in ISO 8601. The time can either be in local or UTC based time. Alternatively, the value may be a duration of time, expressed in the ISO 8601 format as specified in section 3.1.3.8. In this case, the start is relative to another MIME calendar component specified by the RELATED-TO property. Events may have a start date/time but no end date/time. In that case, the event does not take up any time. The following is an example of this property: DTSTART:19960401T235959-0600 This property is optional for MIME entities conforming to this content type. The default data type for this property is DATE-TIME. Optionally, the data type may be DURATION. 3.1.6.28 Status This property is identified by the property name STATUS. This property defines the status associated with the MIME calendar component. This property can only be used when the ATTENDEE property is either not supported or not needed. The following is an example of this property: STATUS:TENTATIVE The property can have the following values: Description Property Dawson/Stenerson 44 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 Value Indicates to-do ACCEPTED was accepted Indicates event NEEDS ACTION or to-do requires action Indicates event SENT or to-do was sent out. Indicates event TENTATIVE is tentatively accepted Indicates event CONFIRMED is confirmed Indicates event DECLINED or to-do has been declined Indicates to-do COMPLETED has been completed Indicates event DELEGATED or to-do has been delegated Indicates the CANCELED event or to-do has been canceled and/or this attendee has been removed from the list of attendees. The default value for this property is NEEDS ACTION. This property is required for MIME entities containing a to-do calendar component conforming to this content type. This property is optional for MIME entities containing an event calendar component conforming to this content type. The data type for this property is STRING. Dawson/Stenerson 45 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 3.1.6.29 Summary This property is identified by the property name SUMMARY. This property defines a short summary or subject of the MIME calendar component. The following is an example of this property: SUMMARY:Department Party This property is required for MIME entities conforming to this content type. The data type for this property is STRING. 3.1.6.30 Time Transparency This property is identified by the property name TRANSP. This property defines whether the event is transparent to free time searches. The value of this property is a number. A value of zero (ASCII decimal 48) guarantees that the entry will blocks time and will be factored into a free time search. A value of one (ASCII decimal 49) specifies that the entry will not block time and will not be factored into a free time search. Any values greater than _1_ will provide implementation specific transparency semantics. Some implementations may treat values greater than one as non-blocking or transparent events. Other implementations may use the numeric value to provide a layering of levels of transparency. The default value is zero (ASCII decimal 48), the event is not transparent and will block free time searches. The following is an example of this property: TRANSP:0 This property is optional for MIME entities conforming to this content type. The data type for this property is INTEGER. 3.1.6.31 Uniform Resource Locator This property is identified by the property name URL. This property defines a Uniform Resource Locator for an Internet location that can be used to obtain real-time information associated with the MIME calendar component. Valid values for this property are a string conforming to [RFC 1738]. The following is an example of this property: URL:http://abc.com/pub/calendars/jsmith/mytime.or3 This property is optional for MIME entities conforming to this content type. The data type for this property is URL. 3.1.6.32 Unique Identifier This property is identified by the property name UID. This property defines a persistent, globally unique identifier associated with the MIME calendar component. Some examples of forms of unique identifiers would include ISO 9070 formal public identifiers (FPI), X.500 distinguished names, machine-generated _random_ numbers with a statistically high likelihood of being globally unique and Uniform Dawson/Stenerson 46 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 Resource Locators (URL). If an URL is specified, it is suggested that the URL reference a service which can provide an updated version of the MIME calendar component. The following is an example of this property: UID:19960401-080045-4000F192713-0052 This property is an important method for group scheduling applications to match calendar entities with later modification or deletion requests. Calendaring and scheduling applications that do not generate this property in MIME calendar components may be limiting their interoperability with other group scheduling applications. This property is optional for MIME entities conforming to this content type. The default data type for this property is STRING. Optionally, the data type may be URL, MID, or CID. 3.1.6.33 Non-standard Properties The MIME Calendaring and Scheduling Content Type provides a _standard mechanism for doing non-standard things_. This extension support is provided for implementers to _push the envelope_ on the existing version of the specification. Extension properties are specified by property and/or property parameter names that have the initial sub- string of X- (the two character sequence: Capital X character followed by the Dash character). It is recommended that vendors concatenate onto this sentinel an added short sub-string to identify the vendor. This will facilitate readability of the extensions and minimize possible collision of names between different vendors. User agents that support this content type are expected to be able to parse the extension properties and property parameters but may ignore them. The following might be the ABC vendor's extension for an audio- clip form of subject property: X-ABC-MMSUBJ;TYPE=WAVE; VALUE=URL: http://load.noise.org/mysubj.wav At present, there is no registration authority for names of extension properties and property parameters. The data type for this property is STRING. Optionally, the data type may be any of the other valid data types. 3.2 Formal Definition The following modified Backus-Naur Notation (BNF) is provided to assist developers in building parsers for the properties of this MIME content type.. This syntax is written according to the form described in RFC 822,but it references just this small subset of RFC 822 literals: CR = ; ( 15, 13.) LF = ; ( 12, 10.) Dawson/Stenerson 47 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 CRLF = CR LF SPACE = ; ( 40, 32.) HTAB = ; ( 11, 9.) All literal property names are valid as upper, lower, or mixed case. ws = 1*(SPACE / HTAB) ; _whitespace,_ one or more spaces or tabs wsls = 1*(SPACE / HTAB / CRLF) ; whitespace with line separators value = 7bit / 8bit / quoted-printable / base64 ; The value must be in the encoding type specified for the ; property value. 7bit = <7bit us-ascii printable chars, excluding CR LF> 8bit = quoted-printable = base64 = ; the end of the text is marked with two CRLF sequences ; this results in one blank line before the start of the next ; property word = vcal_file = [wsls] vcal [wsls] vcal = _BEGIN_ [ws] _:_ [ws] _VCALENDAR_ [ws] 1*CRLF calprop calentities [ws] *CRLF _END_ [ws] _:_ [ws] _VCALENDAR_ [ws] 1*CRLF calentities = calentities *CRLF calentity / calentity calentity = evententity / todoentity Dawson/Stenerson 48 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 evententity = _BEGIN_ [ws] _:_ [ws] _VEVENT_ [ws] 1*CRLF entprops [ws] *CRLF _END_ [ws] _:_ [ws] _VEVENT_ [ws] 1*CRLF todoentity = _ _ BEGIN [ws] _:_ [ws] _VTODO_ [ws] 1*CRLF entprops [ws] *CRLF _END_ [ws] _:_ [ws] _VTODO_ [ws] 1*CRLF calprops = calprops *CRLF calprop / calprop calprop = _PROFILE_ [parms] _:_ value CRLF / _DAYLIGHT_ [params] _:_ value CRLF / _CALENDAR_ [params] _:_ _GREGORIAN_ CRLF / _GEO_ [params] _:_ value CRLF / _PRODID_ [params] _:_ value CRLF / _TZ_ [params] _:_ value CRLF / _VERSION_ _:_ _1.0_ CRLF ; The VERSION calendar property MUST appear in the MIME Calendar ; Object. entprops = entprops *CRLF entprop / entprop entprop = [ws] simprop [params] _:_ value CRLF / [ws] _AALARM_ Dawson/Stenerson 49 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 [params] _:_ aalarmparts CRLF / [ws] _CATEGORIES_ [params] _:_ 1*catvals CRLF / [ws] _CLASS_ [params] _:_ classvals CRLF / [ws] _DALARM_ [params] _:_ dalarmparts CRLF / [ws] _EXDATE_ [params] _:_ xdatevals CRLF / [ws] _MALARM_ [params] _:_ malarmparts CRLF / [ws] _PALARM_ [params] _:_ palarmparts CRLF / [ws] _RDATE_ [params] _:_ rdatevals CRLF / [ws] _RESOURCES_ [params] _:_ 1*resvals CRLF / [ws] _STATUS_ [params] _:_ statvals CRLF simprop = _ATTACH_ / _ATTENDEE_ / _DCREATED_ / _COMPLETED_ / _DESCRIPTION / _ _DTSTART_ / _DUE_ / _DTEND_ / _EXRULE_ / _LAST-MODIFIED_ / _LOCATION_ / _RNUM_ / _PRIORITY_ / _RELATED-TO_ / _RESPONSE-SEQUENCE_ / _RRULE_ / _SEQUENCE_ / _SUMMARY_ / _TRANSP_ / _URL_ / _UID_ / _X-_ word aalarmparts = 0*3(strnosemi _;_) strnosemi ; runTime, snoozeTime, repeatCount, audioContent Dawson/Stenerson 50 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 catvals = _APPOINTMENT_ / _BUSINESS_ / _EDUCATION_ / _HOLIDAY_ / _MEETING_ / _MISCELLANEOUS_ / _NOT-IN-OFFICE_ / _NON-WORKING-HOURS_ / _PERSONAL_ / _PHONE CALL_ / _SICK DAY_ / _SPECIAL OCCASION_ / _TRAVEL_ / _VACATION_ / _X-_ word / value classvals = _PUBLIC_ / _PRIVATE_ / _CONFIDENTIAL_ / _X-_ word / value dalarmparts = 0*3(strnosemi _;_) strnosemi ; runTime, snoozeTime, repeatCount, displayString malarmparts = 0*5(strnosemi _;_) strnosemi ; runTime, snoozeTime, repeatCount, addressString, ; subjectstring, noteString palarmparts = 0*3(strnosemi _;_) strnosemi ; runTime, snoozeTime, repeatCount, procedureName rdatevals = 1*value ; One or more date/time values resvals = _CATERING_ / _CHAIRS_ / _EASEL_ / _PROJECTOR_ / _VCR_ / _VEHICLE_ / _X-_ word / value statvals = _ACCEPTED_ / _NEEDS ACTION_ / _SENT_ / _TENTATIVE_ / _CONFIRMED_ / _DECLINED_ / _COMPLETED_ / _DELEGATED_ / _X-_ word / value params = _;_ [ws] paramlist paramlist = paramlist [ws] _;_ [ws] param / param param = _TYPE_ [ws] _=_ [ws] ptypeval / [_VALUE_ [ws] _=_ [ws]] pvalueval / [_ENCODING_ [ws] _=_ [ws]] pencodingval / _CHARSET_ [ws] _=_ [ws] charsetval Dawson/Stenerson 51 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 / _DATATYPE_ [ws] _=_ [ws] dtypeval / _LANGUAGE_ [ws] _=_ [ws] langval / _MEMBER_ [ws] _=_ [ws] / _ROLE_ [ws] _=_ [ws] roleval / _STATUS_ [ws] _=_ [ws] statuval / _X-_ word [ws] _=_ [ws] word / knowntype ptypeval = knowntype / attendtype / _X-_ word knowntype = _ _ BASIC / _WAVE_ / _X-_ word / value attendtype = _INDIVIDUAL_ / _GROUP_ / _RESOURCE_ / _UNKNOWN_ pvalueval = _INLINE_ / _URL_ / _CONTENT-ID_ / _CID_ / / _MESSAGE-ID_ / _MID_ / _X-_ word pencodingval = _7BIT_ / 8BIT _ _ / _QUOTED-PRINTABLE_ / _BASE64_ / _X-_ word charsetval = dtypeval = _AALARM_ / _BOOLEAN_ / _CID_ / _DALARM_ / _DATE-TIME_ / _DST-RULE_ / _D-T-LIST_ / _DURATION_ / _FLOAT_ / _FLOAT-LIST_ _ / INTEGER_ / _INTEGER-LIST_ / _MALARM_ / _MID / _ _ PALARM_ / RFC822-ADDRESS _ _ / _RRULE_ / _STRING_ / _STRING-LIST_ / _TIME-OFFSET_ / _URL_ / _X-_ word langval = roleval = _ATTENDEE_ / _ORGANIZER_ / _OWNER_ / _X-_ word statusval = _ACCEPTED_ / _ _ / NEEDS ACTION _SENT_ / _TENTATIVE_ / _CONFIRMED_ / _DECLINED_ / _COMPLETED_ / _DELEGATED_ / _X-_ word strnosemi = *(*nonsemi (_\;_ / _\_ CRLF)) *nonsemi Dawson/Stenerson 52 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 ; To include a semicolon in this string, it must be escaped ; with a _\_ character. nonsemi = 3.3 Basic Recurrence Rule Grammar The specification of recurring events can be simplified by the use of a grammar or rule notation. This specification makes use of the Base Recurrence Rule Grammar from the [XAPIA]. A recurrence rule is a string or clear-text encoding of a recurrence specification. A recurrence rule is composed of several components. A rule begins with a frequency which describes the type of repeating event (e.g., daily, weekly, etc.). This is followed by an interval which indicates how often the frequency repeats (i.e., daily, every third day, etc.). This can be followed by optional frequency modifier information and either an end date or a duration. Below is the form of a typical rule. This example causes events to be generated every other week on Tuesday and Thursday, for 8 occurrences: W2 TU TH #4 Where, W is the Frequency, 2 is the Interval, TU and TH are the optional Frequency Modifiers, and #4 is the Duration. The basic recurrence rule grammar supports six types of repetition. The six types follow the same form with only the frequency name and optional modifier information changing from one type of frequency to the next. 3.3.1 Daily Rule The daily rule is used for specifying repeating events based on an interval of a day or more. These can range from every day to every 200th day and beyond. The daily rule begins with the letter D followed by an interval (representing days) and an optional duration or end date. Some examples follow: Daily for 10 occurrences: D1 #10 Daily until 12/24/94: D1 19941224T000000Z Every other day - forever: D2 #0 Dawson/Stenerson 53 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 Every 10 days, 5 occurrences: D10 #5 3.3.2 Weekly Rule The weekly rule is used for specifying repeating events based on an interval of a week or more. The basic weekly rule has the same form as the daily rule except that the rule begins with a W and can contain an optional list of weekdays the events are generated on. For weekly rules, the interval represents weeks. Some examples follow: Weekly for 10 occurrences: W1 #10 Weekly until 12/24/94: W1 19941224T000000Z Every other week - forever: W2 #0 Weekly on Tuesday and Thursday for 5 weeks: W1 TU TH #5 Every other week on Monday Wednesday and Friday until 12/24/94: W2 MO WE FR 19941224T000000Z 3.3.3 Monthly Rule The monthly rule is used for specifying repeating events base on an interval of a month or more. There are two types of monthly recurrence rules. One for by-position and one for by-day. The by- position rule allows weekdays in the month to be specified in relation to their occurrence in the month. An example would be to specify the third Sunday of the month or the last Friday of the month. An occurrence specifier may be used in monthly by-position rules. The occurrence specifiers control which occurrence of a weekday in a month an event occurs on: 1+, 2+, ... 5+ for the first occurrence, second, ...fifth occurrence of the month. 1-, 2-, ... 5- for the last occurrence, second to last occurrence, etc. A 2+ FR SA would indicate the second occurrence of Friday and Saturday in the month. A 1- MO would indicate the first occurrence of Monday working from the end of the month backwards (i.e., the last occurrence). A 2- MO would be the second to the last Monday of the month. A by-day rule allows actual day numbers to be specified such as the 12th day or 29th day. Dawson/Stenerson 54 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 The by-position rule begins with a MP and the by-day rule begins with a MD. The interval in monthly rules represents months. Some examples follow: Monthly on the 1st Friday for ten occurrences: MP1 1+ FR #10 Monthly on the 1st Friday until 12/24/94: MP1 1+ FR 19941224T000000Z Every other month on the 1st and last Sunday of the month for 10 occurrences: MP2 1+ SU 1- SU #10 Every six months on the 2nd Monday through Friday for 10 occurrences: MP6 2+ MO TU WE TH FR #10 Monthly on the second last Monday of the month for 6 months: MP1 2- MO #6 Monthly on the third to the last day of the month, forever: MD1 3- #0 Monthly on the 2nd and 15th of the month for 10 occurrences: MD1 2 15 #10 In the next example LD refers to _LastDay_ in a monthly recurrence rule. Monthly on the 1st and last day of the month for 10 occurrences: MD1 1 LD #10 or MD1 1 1- #10 Every 18 months on the 10th through 15th of the month for 10 occurrences: MD18 10 11 12 13 14 15 #10 Monthly on the second to the last day for 5 months. So, if the start date is August 1996, the event would repeat on 8/30/96, 9/29/96, 10/30/96, 11/29/96, and 12/30/96: MD1 2- #5 3.3.4 Yearly Rule The yearly rule is used for specifying repeating events based on an interval of a year or more. There are two types of yearly recurrence rules. One for by-month and one for by-day. The by-month rule allows specific months out of the year to be specified. The by-day allows specific days to be specified. In the by-month rule, the day in the month the rule is to occur on is determined from the initial appointment. Dawson/Stenerson 55 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 The by-month rule begins with a YM and the by-day rule begins with a YD. The interval in yearly rules represents years. Some examples follow: Yearly in June and July for 10 occurrences: YM1 6 7 #10 Every other year on January, Feb, and March for 10 occurrences: YM2 1 2 3 #10 Every 3rd year on the 1st, 100th and 200th day for 10 occurrences: YD3 1 100 200 #10 3.3.5 Grammar [Editor's Note: The format of this BNF will be changed to the RFC 822 ABNF in the next version of the draft.] {} 0 or more [] 0 or 1 start ::= [] | [] | [] | [] | [] | [] digit ::= <0|1|2|3|4|5|6|7|8|9> digits ::= {} enddate ::= ISO 8601_date_time value(e.g., 19940712T101530Z) interval ::= duration ::= # lastday ::= LD plus ::= + minus ::= - daynumber ::= <1-31> [|]| daynumberlist ::= daynumber {} Dawson/Stenerson 56 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 month ::= <1-12> monthlist ::= {} day ::= <1-366> daylist ::= {} occurrence ::= <1-5> | <1-5> weekday ::= weekdaylist ::= {} occurrenceweekday ::= [] occurenceweekdaylist ::= {} daily ::= D [] weekly ::= W [] [] monthlybypos ::= MP [] [] monthlybyday ::= MD [] [] yearlybymonth ::= YM [] [] yearlybyday ::= YD [] [] 3.3.6 Grammar Glossary enddate Controls when a repeating event terminates. The enddate is the last time an event can occur. Interval Defines the frequency in which a rule repeats. duration Controls the number of events a rule generates. Lastday Can be used as a replacement to daynumber to indicate the last day of the month. daynumber A number representing a day of the month. month A number representing a month of the year. day A number representing a day of the year. occurrence Controls which week of the month a particular weekday event occurs. Dawson/Stenerson 57 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 weekday A symbol representing a day of the week. daily Defines a rule that repeats on a daily basis. weekly Defines a rule that repeats on a weekly basis. monthlybypos Defines a rule that repeats on a monthly basis on a relative day and week. monthlybyday Defines a rule that repeats on a monthly basis on an absolute day. yearlybymonth Defines a rule that repeats on specific months of the year. yearlybyday Defines a rule that repeats on specific days of the year. 3.3.7 Policies 1. The duration portion of a rule defines the total number of events the rule generates, including the first event. 2. Information, not contained in the rule, necessary to determine the next event time and date is derived from the Start Time entry attribute. 3. If an end date and a duration is specified in the rule, the recurring event ceases when the end date is reached or the number of events indicated in the duration occur; whichever comes first. 4. If the duration or an end date is not established in the rule (e.g., D4) the event occurs twice. That is D4 is equivalent to D4 #2. 5. A duration of #0 means repeat this event forever. 6. Using the occurrence specifier 5+ (e.g. 5th Friday) or 5- (e.g. 5th from last Friday) in a month that does not contain 5 weeks does not generate an event and thus does not count against the duration. The same applies to providing a day of the month that does not occur in the month. For example the 30th or 31st . 7. The start time and date of an entry must be synchronized with one of the repeating events defined by its recurrence rule. The following is not allowed: Initial Appointment Date: 7/1/94 (Friday) Recurrence Rule: W1 MO TH #5 The following is acceptable: Initial Appt Date: 7/1/94 (Friday) Recurrence Rule: W1 MO FR #5 or W1 #5 Dawson/Stenerson 58 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 8. If the optional and information is missing from a occurrence the information is derived from the entry attributes. The used in the recurring event is a count from the beginning of the month to the entry date and the used is the day of the week the entry is scheduled to occur on. 9. If the occurrence or occurrence does not list a week day (e.g., SU or day 10) in the rule, the week day is established from the entry attribute information. As an example the rule MP1 #3 used in an entry with a start date of 7/20/94 (which is the third Wednesday of the month) repeats on 8/17/94 which is the third Wednesday of the month. 4. Registration of Content Type Profiles This section defines procedures by which usage profiles for the MIME Calendaring and Scheduling Content Type are registered with the IANA and made available to the Internet community. Note that non-IANA profiles may be used by bilateral agreement, provided the associated profile names follow the "X-" convention defined above in section 3.1.6.33. The procedures defined here are designed to allow public comment and review of new profiles, while posing only a small impediment to the definition of new profiles. Registration of a new profile is accomplished by the following steps. 4.1 Define the profile A profile is defined by completing the following template. To: ietf-calendar@imc.org Subject: Registration of text/calendar MIME profile XXX Profile name: Profile purpose: Profile type-subtype: Profile special notes (optional): Intended usage: (one of COMMON, LIMITED USE or OBSOLETE) The explanation of what goes in each field in the template follows. Profile name: The name of the profile as it will be generally referred to in public. This name is required in the profile. Dawson/Stenerson 59 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 Profile purpose: The purpose of the profile (e.g., to schedule document management updates, etc.). Give a short but clear description. This description is required in the profile. Profile type-subtype: The type-subtypes of the profile as they will appear in the text/calendar MIME Content-Type Profile parameter. This list of type-subtype values is required in the profile. Profile properties: The list of MIME Calendaring and Scheduling Content Type properties associated with the profile. This list of properties that are included in the profile. If a property is required by the profile, it should noted in this section. Other types not mentioned in the profile definition may also be present. Note that any new properties referenced by the profile must be defined separately as described in section . Profile special notes: Any special notes about the profile, how it is to be used, etc. This section is not required in the profile. 4.2 Post the profile definition The profile description must be posted to the IETF Calendaring and Scheduling Working Group discussion list, ietf-calendar@imc.org. 4.3 Allow a comment period Discussion on the new profile must be allowed to take place on the list for a minimum of two weeks. Consensus must be reached on the profile before submitting the profile for approval. 4.4 Submit the profile for approval Once the two-week comment period has elapsed, and the proposer is convinced consensus has been reached on the profile, the registration application should be submitted to the Profile Reviewer for approval. The Profile Reviewer is appointed to the Application Area Directors and may either accept or reject the profile registration. An accepted registration should be passed on by the Profile Reviewer to the IANA for inclusion in the official IANA profile registry. The registration may be rejected for any of the following reasons. 1) Insufficient comment period; 2) Consensus not reached; 3) Technical deficiencies raised on the list or elsewhere have not been addressed. The Profile Reviewer's decision to reject a profile may be appealed by the proposer to the IESG, or the objections raised can be addressed by the proposer and the profile resubmitted. 4.5 Profile Change Control Existing profiles may be changed using the same process by which they were registered. 1. Define the change Dawson/Stenerson 60 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 2. Post the change 3. Allow a comment period 4. Submit the profile for approval Note that the original author or any other interested party may propose a change to an existing profile, but that such changes should only be proposed when there are serious omissions or errors in the published specification. The Profile Reviewer may object to a change if it is not backwards compatible, but is not required to do so. Profile definitions can never be deleted from the IANA registry, but profiles which are no longer believed to be useful can be declared OBSOLETE by a change to their "intended use" field. 4.6 Registration of New Content Type Properties This section defines procedures by which new properties for the MIME Calendaring and Scheduling Content Type are registered with the IANA. Note that non-IANA properties may be used by bilateral agreement, provided the associated properties names follow the "X-" convention defined above in section 3.1.6.33. The procedures defined here are designed to allow public comment and review of new properties, while posing only a small impediment to the definition of new properties. Registration of a new property is accomplished by the following steps. 4.6.1 Define the property A property is defined by completing the following template. To: ietf-calendar@imc.org Subject: Registration of text/calendar MIME property XXX Property name: Property purpose: Property data type(s): Property encoding: Property special notes (optional): Intended usage: (one of COMMON, LIMITED USE or OBSOLETE) The meaning of each field in the template is as follows. Dawson/Stenerson 61 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 Property name: The name of the property, as it will appear in the body of an text/calendar MIME Content-Type "property: value" line to the left of the colon ":". Property purpose: The purpose of the property (e.g., to indicate a delegate for the event or to-do, etc.). Give a short but clear description. Property data type(s): Any of the valid data types for the property value needs to be specified. The default data type also needs to be specified. If a new data type is specified, it needs to be declared in this section. Property encoding: The encodings permitted for the property value. This description must be precise and must not violate the general encoding rules defined in this document. Property special notes: Any special notes about the property, how it is to be used, etc. 4.6.2 Post the Property definition The property description must be posted to the new property discussion list, ietf-calendar@imc.org. 4.6.3 Allow a comment period Discussion on the new property must be allowed to take place on the list for a minimum of two weeks. Consensus must be reached on the property before proceeding to the next step. 4.6.4 Submit the property for approval Once the two-week comment period has elapsed, and the proposer is convinced consensus has been reached on the property, the registration application should be submitted to the Profile Reviewer for approval. The Profile Reviewer is appointed to the Application Area Directors and may either accept or reject the property registration. An accepted registration should be passed on by the Profile Reviewer to the IANA for inclusion in the official IANA profile registry. The registration may be rejected for any of the following reasons. 1) Insufficient comment period; 2) Consensus not reached; 3) Technical deficiencies raised on the list or elsewhere have not been addressed. The Profile Reviewer's decision to reject a property may be appealed by the proposer to the IESG, or the objections raised can be addressed by the proposer and the property resubmitted. 4.7 Content Type Property Change Control Existing properties may be changed using the same process by which they were registered. Dawson/Stenerson 62 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 1. Define the change 2. Post the change 3. Allow a comment period 4. Submit the property for approval Note that the original author or any other interested party may propose a change to an existing property, but that such changes should only be proposed when there are serious omissions or errors in the published specification. The Profile Reviewer may object to a change if it is not backwards compatible, but is not required to do so. Property definitions can never be deleted from the IANA registry, but properties which are no longer believed to be useful can be declared OBSOLETE by a change to their "intended use" field. 5. File extension The file extension of _vcs_ is to be used to designate a file containing calendaring and scheduling information consistent with this MIME content type. 6. Macintosh File Type Code The file type code of _vcal_ is to be used in Apple MacIntosh operating system environments to designate a file containing calendaring and scheduling information consistent with this MIME media type. 7. Bibliography The following document are referred to within this document. [ISO 8601] ISO 8601, Data elements and interchange formats_ Information interchange_Representation of dates and times, International Organization for Standardization, June, 1988. This standard is also addressed by the Internet Draft document ftp://ds.internic.net/internet-drafts/draft-newman-datetime-00.txt. [ISO 9070] ISO/IEC 9070, Information Technology_SGML Support Facilities_Registration Procedures for Public Text Owner Identifiers, Second Edition, International Organization for Standardization, April, 1991. [MIME-REG] Freed, N., Postel, J., "Multipurpose Internet Mail Extensions (MIME) - Part Four: Registration Procedures", Internet- Draft draft-ietf-822ext-mime-reg-02.txt, December 1995. [RFC 1738] T. Berners-Lee and L. Masinter , _Universal Resource Locator_, RFC 1738, Xerox Corporation, University of Minnesota, December 1994. Dawson/Stenerson 63 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 [RFC 1766] H. Alvestrand, _Tags for the Identification of Languages_, UNINETT, RFC 1766, March 1995. [RFC 2045] Borenstein, N., and N. Freed, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996. [RFC 2046] Borenstein N., and N. Freed, "Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types", RFC 2046, November 1996. [US-ASCII] Coded Character Set--7-bit American Standard Code for Information Interchange, ANSI X3.4-1986. [VCAL] MIME calendaring entity - Calendaring and Scheduling Exchange Format, Versit Consortium, September 18, 1996. [XAPIA] XAPIA CSA, Calendaring and Scheduling Application Programming Interface (CSA) Version 1.0, X.400 API Association, November 15, 1994. 8. Acknowledgments A hearty thanks to the IETF Calendaring and Scheduling Working Group and also the following individuals who have participated in the drafting, review and discussion of this memo: Roland Alden, Harald T. Alvestrand, Denis Bigorgne, John Binici, Bill Bliss, Andre Courtemanche, Dave Crocker, Alec Dun, Ross Finlayson, Randell Flink, Ned Freed, Patrik Falstrom, Chuck Grandgent, Mark Handley, Steve Hanna, Paul B. Hill, Mark Horton, Bruce Kahn, C. Harald Koch, Theodore Lorek, Keith Moore, Cecil Murray, Chris Newman, Ralph Patterson, Pete Resnick, Keith Rhodes, Robert Ripberger, Andras Salamar, Vinod Seraphin, Ken Shan, Andrew Shuman, William P. Spencer, Mark Towfiq, Robert Visnov, James L. Weiner, Mike Weston, William Wyatt. 9. Author's Address The following address information is provided in a MIME-VCARD, Electronic Business Card, format. The authors of this draft are: BEGIN:VCARD FN:Frank Dawson ORG:Lotus Development Corporation ADR;WORK;POSTAL;PARCEL:;;6544 Battleford Drive; Raleigh;NC;27613-3502;USA TEL;WORK;MSG:+1-919-676-9515 TEL;WORK;FAX:+1-919-676-9564 EMAIL;INTERNET:fdawson@earthlink.net URL:http://home.earthlink.net/~fdawson END:VCARD Dawson/Stenerson 64 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 BEGIN:VCARD FN:Derik Stenerson ORG:Microsoft Corporation ADR;WORK;POSTAL;PARCEL:;;One Microsoft Way; Redmond;WA;98052-6399;USA TEL;WORK;MSG:+1-206-936-5522 TEL;WORK;FAX:+1-206-936-7329 EMAIL;INTERNET:deriks@Exchange.Microsoft.com END:VCARD The iCalendar Object is a result of the work of the Internet Engineering Task Force Calendaring and Scheduling Working Group. The chairman of that working group is: BEGIN:VCARD FN:Anik Ganguly ORG:OnTime, Inc. ADR;WORK;POSTAL;PARCEL:10 Floor;;21700 Northwestern Highway; Southfield;MI;48075;USA TEL;WORK;MSG:+1-810-559-5955 TEL;WORK;FAX:+1-810-559-5034 EMAIL;INTERNET:anik@ontime.com END:VCARD 10. Examples The following examples are provided as an informational source of illustrative MIME entities containing data consistent with this MIME content type. The following is an example of a MIME message with a single body part consisting of a text/calendar content type. The message specifies a meeting request between the originator and recipient of the message. TO:jsmith@host1.com FROM:jdoe@host1.com MIME-VERSION:2.0 MESSAGE-ID:<19960704 08:30:00 EDT xyz@host1.com> CONTENT-TYPE:text/calendar;PROFILE=request,event BEGIN:VCALENDAR PROFILE:event-request VERSION:2.0 BEGIN:VEVENT DTSTART:19960918T143000Z DTEND:19960920T220000Z CATEGORIES:CONFERENCE;PROJECT SUMMARY:Networld+Interop Conference DESCRIPTION;ENCODING=QUOTED-PRINTABLE:Networld+Interop Conference= and Exhibit=0D=0A= Atlanta World Congress Center=0D=0A= Atlanta, Georgia Dawson/Stenerson 65 Expires August 1997 Internet Draft C&S Core Object Specification February 3, 1997 END:VEVENT END:VCALENDAR The following example message issues a meeting request that does not require any reply. The message is sent as a singular _text/calendar_ content type, body part. From: jsmith@host1.com To: ietf-calendar@imc.org Subject: First IETF-Calendar Working Group Meeting MIME-Version: 2.0 Message-ID: Content-Type: text/calendar;Profile=event,request BEGIN:VCALENDAR PROFILE:event-request DAYLIGHT:TRUE;-06:00;19960407T025959;19961027T010000;EST;EDT PRODID:-//RDU Software//NONSGML HandCal//EN TZ:-05:00 VERSION:2.0 BEGIN:VEVENT ATTENDEE;EXPECT=REQUEST:ietf-calendar@imc.org DESCRIPTION:First IETF-Calendaring and Scheduling Working Group Meeting CATEGORIES:MEETING CLASS:PUBLIC DCREATED:19961022T083000 SUMMARY:IETF Calendaring Working Group Meeting DTSTART:19961210T210000Z DTEND:19961210T220000Z LOCATION:San Jose, CA - Fairmont Hotel UID:guid-1.host1.com END:VEVENT END:VCALENDAR Dawson/Stenerson 66 Expires August 1997