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Daboo 3 Internet-Draft Apple Inc. 4 Intended status: Standards Track June 3, 2016 5 Expires: December 5, 2016 7 New Properties for iCalendar 8 draft-ietf-calext-extensions-03 10 Abstract 12 This document defines a set of new properties for iCalendar data as 13 well as extending the use of some existing properties to the entire 14 iCalendar object. 16 Status of This Memo 18 This Internet-Draft is submitted in full conformance with the 19 provisions of BCP 78 and BCP 79. 21 Internet-Drafts are working documents of the Internet Engineering 22 Task Force (IETF). Note that other groups may also distribute 23 working documents as Internet-Drafts. The list of current Internet- 24 Drafts is at http://datatracker.ietf.org/drafts/current/. 26 Internet-Drafts are draft documents valid for a maximum of six months 27 and may be updated, replaced, or obsoleted by other documents at any 28 time. It is inappropriate to use Internet-Drafts as reference 29 material or to cite them other than as "work in progress." 31 This Internet-Draft will expire on December 5, 2016. 33 Copyright Notice 35 Copyright (c) 2016 IETF Trust and the persons identified as the 36 document authors. All rights reserved. 38 This document is subject to BCP 78 and the IETF Trust's Legal 39 Provisions Relating to IETF Documents 40 (http://trustee.ietf.org/license-info) in effect on the date of 41 publication of this document. Please review these documents 42 carefully, as they describe your rights and restrictions with respect 43 to this document. Code Components extracted from this document must 44 include Simplified BSD License text as described in Section 4.e of 45 the Trust Legal Provisions and are provided without warranty as 46 described in the Simplified BSD License. 48 Table of Contents 50 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 51 2. Conventions Used in This Document . . . . . . . . . . . . . . 3 52 3. Backwards Compatible Extension Properties . . . . . . . . . . 3 53 4. Modifications to Calendar Components . . . . . . . . . . . . 3 54 5. Properties . . . . . . . . . . . . . . . . . . . . . . . . . 5 55 5.1. NAME Property . . . . . . . . . . . . . . . . . . . . . . 5 56 5.2. DESCRIPTION Property . . . . . . . . . . . . . . . . . . 6 57 5.3. UID Property . . . . . . . . . . . . . . . . . . . . . . 6 58 5.4. LAST-MODIFIED Property . . . . . . . . . . . . . . . . . 7 59 5.5. URL Property . . . . . . . . . . . . . . . . . . . . . . 7 60 5.6. CATEGORIES Property . . . . . . . . . . . . . . . . . . . 7 61 5.7. REFRESH-INTERVAL Property . . . . . . . . . . . . . . . . 8 62 5.8. SOURCE Property . . . . . . . . . . . . . . . . . . . . . 9 63 5.9. COLOR Property . . . . . . . . . . . . . . . . . . . . . 9 64 5.10. IMAGE Property . . . . . . . . . . . . . . . . . . . . . 10 65 5.11. CONFERENCE Property . . . . . . . . . . . . . . . . . . . 12 66 6. Property Parameters . . . . . . . . . . . . . . . . . . . . . 13 67 6.1. DISPLAY Property Parameter . . . . . . . . . . . . . . . 13 68 6.2. EMAIL Property Parameter . . . . . . . . . . . . . . . . 14 69 6.3. FEATURE Property Parameter . . . . . . . . . . . . . . . 15 70 6.4. LABEL Property Parameter . . . . . . . . . . . . . . . . 16 71 7. Security Considerations . . . . . . . . . . . . . . . . . . . 16 72 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 73 8.1. Property Registrations . . . . . . . . . . . . . . . . . 17 74 8.2. Parameter Registrations . . . . . . . . . . . . . . . . . 17 75 8.3. Display Types Registry . . . . . . . . . . . . . . . . . 18 76 8.4. Feature Types Registry . . . . . . . . . . . . . . . . . 18 77 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 18 78 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 18 79 10.1. Normative References . . . . . . . . . . . . . . . . . . 18 80 10.2. Informative References . . . . . . . . . . . . . . . . . 19 81 Appendix A. Change History (To be removed by RFC Editor before 82 publication) . . . . . . . . . . . . . . . . . . . . 19 83 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 22 85 1. Introduction 87 The iCalendar [RFC5545] data format is used to represent calendar 88 data and is used with iTIP [RFC5546] to handle scheduling operations 89 between calendar users. iCalendar is in widespread use, and in 90 accordance with provisions in that specification, extension elements 91 have been added by various vendors to the data format in order to 92 support and enhance capabilities. This specification collects a 93 number of these ad-hoc extensions and uses the new IANA registry 94 capability defined in [RFC5545] to register standard variants with 95 clearly defined definitions and semantics. In addition, some new 96 elements are introduced for features that vendors have recently been 97 requesting. 99 2. Conventions Used in This Document 101 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 102 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 103 "OPTIONAL" in this document are to be interpreted as described in 104 [RFC2119]. 106 The notation used in this memo is the ABNF notation of [RFC5234] as 107 used by iCalendar [RFC5545]. Any syntax elements shown below that 108 are not explicitly defined in this specification come from iCalendar 109 [RFC5545]. 111 3. Backwards Compatible Extension Properties 113 iCalendar defines properties which can have different value types 114 indicated by a "VALUE" parameter. The definition of a property 115 specifies a "default" value type that is assumed to be used when no 116 "VALUE" parameter is present. However, this poses a problem to 117 iCalendar parser/generator software that does not know about the 118 default values for new properties. For example, if a new property 119 "FOO" were defined with a default value type of URI, and a URI value 120 with a comma was used, an iCalendar generator not aware of this fact 121 would likely treat the property value as "TEXT" and apply backslash 122 escaping to the comma in the value, effectively making it an invalid 123 URI value. 125 To avoid this problem, this specification recommends that all 126 properties not defined in [RFC5545], always include a "VALUE" 127 parameter, if the type is other than "TEXT". i.e., in the example 128 above, the "FOO" property would have a "VALUE=URI" parameter. This 129 allows iCalendar parser/generator software to track the correct types 130 of unknown properties. 132 New properties defined in this specification use the term "no 133 default" in the "Value Type" definition to indicate that the "VALUE" 134 parameter has to be included. 136 4. Modifications to Calendar Components 138 The following changes to the syntax defined in iCalendar [RFC5545] 139 are made here. New elements are defined in subsequent sections. 141 calprops =/ *( 142 ; 143 ; The following are OPTIONAL, 144 ; but MUST NOT occur more than once. 145 ; 146 uid / last-mod / url / 147 refresh / source / color 148 ; 149 ; The following are OPTIONAL, 150 ; and MAY occur more than once. 151 ; 152 name / description / categories / 153 image 154 ; 155 ) 157 eventprop =/ *( 158 ; 159 ; The following are OPTIONAL, 160 ; but MUST NOT occur more than once. 161 ; 162 color / 163 ; 164 ; The following are OPTIONAL, 165 ; and MAY occur more than once. 166 ; 167 image 168 ; 169 ) 171 todoprop =/ *( 172 ; 173 ; The following are OPTIONAL, 174 ; but MUST NOT occur more than once. 175 ; 176 color / 177 ; 178 ; The following are OPTIONAL, 179 ; and MAY occur more than once. 180 ; 181 image 182 ; 183 ) 185 jourprop =/ *( 186 ; 187 ; The following are OPTIONAL, 188 ; but MUST NOT occur more than once. 189 ; 190 color / 191 ; 192 ; The following are OPTIONAL, 193 ; and MAY occur more than once. 194 ; 195 image 196 ; 197 ) 199 5. Properties 201 5.1. NAME Property 203 Property Name: NAME 205 Purpose: This property specifies the name of the calendar. 207 Value Type: TEXT 209 Property Parameters: IANA, non-standard, alternate text 210 representation, and language property parameters can be specified 211 on this property. 213 Conformance: This property can be specified multiple times in an 214 iCalendar object. However, each property MUST represent the name 215 of the calendar in a different language. 217 Description: This property is used to specify a name of the 218 iCalendar object that can be used by calendar user agents when 219 presenting the calendar data to a user. Whilst a calendar only 220 has a single name, multiple language variants can be specified by 221 including this property multiple times with different "LANGUAGE" 222 parameter values on each. 224 Format Definition: This property is defined by the following 225 notation: 227 name = "NAME" nameparam ":" text CRLF 229 nameparam = *( 230 ; 231 ; The following are OPTIONAL, 232 ; but MUST NOT occur more than once. 233 ; 234 (";" altrepparam) / (";" languageparam) / 235 ; 236 ; The following is OPTIONAL, 237 ; and MAY occur more than once. 238 ; 239 (";" other-param) 240 ; 241 ) 243 Example: The following is an example of this property: 245 NAME:Company Vacation Days 247 5.2. DESCRIPTION Property 249 This specification modifies the definition of the "DESCRIPTION" 250 property to allow it to be defined on an iCalendar object. The 251 following additions are made to the definition of this property. 253 Purpose: This property specifies the description of the calendar. 255 Conformance: This property can be specified multiple times in an 256 iCalendar object. However, each property MUST represent the 257 description of the calendar in a different language. 259 Description: This property is used to specify a lengthy textual 260 description of the iCalendar object that can be used by calendar 261 user agents when describing the nature of the calendar data to a 262 user. Whilst a calendar only has a single description, multiple 263 language variants can be specified by including this property 264 multiple times with different "LANGUAGE" parameter values on each. 266 5.3. UID Property 268 This specification modifies the definition of the "UID" property to 269 allow it to be defined on an iCalendar object. The following 270 additions are made to the definition of this property. 272 Purpose: This property specifies the persistent, globally unique 273 identifier for the iCalendar object. This can be used, for 274 example, to identify duplicate calendar streams that a client may 275 have been given access to. It can be used in conjunction with the 276 "LAST-MODIFIED" property also specified on the "VCALENDAR" object, 277 to identify the most recent version of a calendar. 279 Conformance: This property can be specified once in an iCalendar 280 object. 282 5.4. LAST-MODIFIED Property 284 This specification modifies the definition of the "LAST-MODIFIED" 285 property to allow it to be defined on an iCalendar object. The 286 following additions are made to the definition of this property. 288 Purpose: This property specifies the date and time that the 289 information associated with the calendar was last revised. 291 Conformance: This property can be specified once in an iCalendar 292 object. 294 5.5. URL Property 296 This specification modifies the definition of the "URL" property to 297 allow it to be defined on an iCalendar object. The following 298 additions are made to the definition of this property. 300 Purpose: This property may be used to convey a location where a more 301 dynamic rendition of the calendar information can be found. 303 Conformance: This property can be specified once in an iCalendar 304 object. 306 5.6. CATEGORIES Property 308 This specification modifies the definition of the "CATEGORIES" 309 property to allow it to be defined on an iCalendar object. The 310 following additions are made to the definition of this property. 312 Purpose: This property defines the categories for an entire 313 calendar. 315 Conformance: This property can be specified multiple times in an 316 iCalendar object. 318 Description: When multiple properties are present, the set of 319 categories that apply to the iCalendar object are the union of all 320 the categories listed in each property value. 322 5.7. REFRESH-INTERVAL Property 324 Property Name: REFRESH-INTERVAL 326 Purpose: This property specifies a suggested minimum interval for 327 polling for changes of the calendar data from the original source 328 of that data. 330 Value Type: DURATION - no default 332 Property Parameters: IANA and non-standard property parameters can 333 be specified on this property. 335 Conformance: This property can be specified once in an iCalendar 336 object. 338 Description: This property specifies a positive duration that gives 339 a suggested minimum polling interval for checking for updates to 340 the calendar data. The value of this property SHOULD be used by 341 calendar user agents to limit the polling interval for calendar 342 data updates to the minimum interval specified. 344 Format Definition: This property is defined by the following 345 notation: 347 refresh = "REFRESH-INTERVAL" refreshparam 348 ":" dur-value CRLF 349 ;consisting of a positive duration of time. 351 refreshparam = *( 352 ; 353 ; The following is REQUIRED, 354 ; but MUST NOT occur more than once. 355 ; 356 (";" "VALUE" "=" "DURATION") / 357 ; 358 ; The following is OPTIONAL, 359 ; and MAY occur more than once. 360 ; 361 (";" other-param) 362 ; 363 ) 365 Example: The following is an example of this property: 367 REFRESH-INTERVAL;VALUE=DURATION:P1W 369 5.8. SOURCE Property 371 Property Name: SOURCE 373 Purpose: This property identified a URI where calendar data can be 374 refreshed from. 376 Value Type: URI - no default 378 Property Parameters: IANA and non-standard property parameters can 379 be specified on this property. 381 Conformance: This property can be specified once in an iCalendar 382 object. 384 Description: This property identifies a location where a client can 385 retrieve updated data for the calendar. Clients SHOULD honor any 386 specified "REFRESH-INTERVAL" value when periodically retrieving 387 data. Note that this property differs from the "URL" property in 388 that "URL" is meant to provide an alternative representation of 389 the calendar data, rather than the original location of the data. 391 Format Definition: This property is defined by the following 392 notation: 394 source = "SOURCE" sourceparam ":" uri CRLF 396 sourceparam = *(";" other-param) 398 Example: The following is an example of this property: 400 SOURCE;VALUE=URI:https://example.com/holidays.ics 402 5.9. COLOR Property 404 Property Name: COLOR 406 Purpose: This property specifies a color used for displaying the 407 calendar, event, todo, or journal data. 409 Value Type: TEXT 411 Property Parameters: IANA and non-standard property parameters can 412 be specified on this property. 414 Conformance: This property can be specified once in an iCalendar 415 object, or "VEVENT", "VTODO", or "VJOURNAL" calendar components. 417 Description: This property specifies a color that clients MAY use 418 when presenting the relevant data to a user. Typically this would 419 appear as the "background" color of events or tasks. The value is 420 a case-insensitive color name taken from the CSS3 set of names, 421 defined in Section 4.3 of [W3C.REC-css3-color-20110607]. 423 Format Definition: This property is defined by the following 424 notation: 426 color = "COLOR" colorparam ":" text CRLF 427 ; Value is CSS3 color name 429 colorparam = *(";" other-param) 431 Example: The following is an example of this property: 433 COLOR:turquoise 435 5.10. IMAGE Property 437 Property Name: IMAGE 439 Purpose: This property specifies an image associated with the 440 calendar or a calendar component. 442 Value Type: URI or BINARY - no default. The value MUST refer to or 443 be data with a media type of "image". 445 Property Parameters: IANA, non-standard, display, inline encoding, 446 and value data type property parameters can be specified on this 447 property. The format type parameter can be specified on this 448 property and is RECOMMENDED for inline binary encoded content 449 information. 451 Conformance: This property can be specified multiple times in an 452 iCalendar object, or "VEVENT", "VTODO", or "VJOURNAL" calendar 453 components. 455 Description: This property specifies an image for an iCalendar 456 object or a calendar component via a uri or directly with inline 457 data that can be used by calendar user agents when presenting the 458 calendar data to a user. Multiple properties MAY be used to 459 specify alternative sets of images with, for example, varying 460 media subtypes, resolutions or sizes. When multiple properties 461 are present, calendar user agents SHOULD display only one of them, 462 picking one that provides the most appropriate image quality, or 463 display none. The "DISPLAY" parameter is used to indicate the 464 intended display mode for the image. The "ALTREP" parameter, 465 defined in [RFC5545], can be used to provide a "clickable" image 466 where the URI in the parameter value can be "launched" by a click 467 on the image in the calendar user agent. 469 Format Definition: This property is defined by the following 470 notation: 472 image = "IMAGE" imageparam 473 ( 474 ( 475 ";" "VALUE" "=" "URI" 476 ":" uri 477 ) / 478 ( 479 ";" "ENCODING" "=" "BASE64" 480 ";" "VALUE" "=" "BINARY" 481 ":" binary 482 ) 483 ) 484 CRLF 486 imageparam = *( 487 ; 488 ; The following is OPTIONAL for a URI value, 489 ; RECOMMENDED for a BINARY value, 490 ; and MUST NOT occur more than once. 491 ; 492 (";" fmttypeparam) / 493 ; 494 ; The following are OPTIONAL, 495 ; and MUST NOT occur more than once. 496 ; 497 (";" altrepparam) / (";" displayparam) / 498 ; 499 ; The following is OPTIONAL, 500 ; and MAY occur more than once. 501 ; 502 (";" other-param) 503 ; 504 ) 506 Example: The following is an example of this property: 508 IMAGE;VALUE=URI;DISPLAY=BADGE;FMTTYPE=image/png:h 509 ttp://example.com/images/party.png 511 5.11. CONFERENCE Property 513 Property Name: CONFERENCE 515 Purpose: This property specifies information for accessing a 516 conferencing system. 518 Value Type: URI - no default. 520 Property Parameters: IANA, non-standard, feature, and label property 521 parameters can be specified on this property. 523 Conformance: This property can be specified multiple times in a 524 "VEVENT" or "VTODO" calendar component. 526 Description: This property specifies information for accessing a 527 conferencing system for attendees of a meeting or task. This 528 might be a tel: URI [RFC3966] for a telephone-based conference 529 number dial-in (with access codes included), or it might be an 530 http: or https: URI [RFC7230] for a web-based video chat, or a URI 531 for an instant messaging group chat room. If a specific URI for a 532 conferencing system is not available, a data: URI [RFC2397] 533 containing a text description can be used. 535 A conference system can be a bi-directional communication channel, 536 or a uni-directional "broadcast feed". 538 The "FEATURE" property parameter is used to describe the key 539 capabilities of the conference system to allow a client to choose 540 the ones that give the required level of interaction from a set of 541 multiple properties. 543 The "LABEL" property paramater is used to convey additional 544 details on the use of the URI. For example, the URIs or access 545 codes for the moderator and attendee of a teleconference system 546 could be different, and the "LABEL" property parameter could be 547 used to "tag" each "CONFERENCE" property to indicate which is 548 which. 550 Format Definition: This property is defined by the following 551 notation: 553 conference = "CONFERENCE" confparam ":" uri CRLF 555 confparam = *( 556 ; 557 ; The following is REQUIRED, 558 ; but MUST NOT occur more than once. 559 ; 560 (";" "VALUE" "=" "URI") / 561 ; 562 ; The following are OPTIONAL, 563 ; and MUST NOT occur more than once. 564 ; 565 (";" featureparam) / (";" labelparam) / 566 ; 567 ; The following is OPTIONAL, 568 ; and MAY occur more than once. 569 ; 570 (";" other-param) 571 ; 572 ) 574 Example: The following are examples of this property: 576 CONFERENCE;VALUE=URI;FEATURE=PHONE,MODERATOR; 577 LABEL=Moderator dial-in:tel:+1-412-555-0123,,,654321 578 CONFERENCE;VALUE=URI;FEATURE=PHONE; 579 LABEL=Attendee dial-in:tel:+1-412-555-0123,,,555123 580 CONFERENCE;VALUE=URI;FEATURE=PHONE; 581 LABEL=Attendee dial-in:tel:+1-888-555-0456,,,555123 582 CONFERENCE;VALUE=URI;FEATURE=CHAT; 583 LABEL=Chat room:xmpp:chat-123@conference.example.com 584 CONFERENCE;VALUE=URI;FEATURE=AUDIO,VIDEO; 585 LABEL=Attendee dial-in:https://chat.example.com/audio?id=123456 587 6. Property Parameters 589 6.1. DISPLAY Property Parameter 591 Parameter Name: DISPLAY 593 Purpose: To specify different ways in which an image for a calendar 594 or component can be displayed. 596 Format Definition: This property parameter is defined by the 597 following notation: 599 displayparam = "DISPLAY" "=" displayval *("," displayval) 601 displayval = ("BADGE" / ; image inline with the title of the 602 ; event 603 "GRAPHIC" / ; a full image replacement for the event 604 ; itself 605 "FULLSIZE" / ; an image that is used to enhance the 606 ; event 607 "THUMBNAIL" / ; a smaller variant of "FULLSIZE" to be 608 ; used when space for the image is 609 ; constrained 610 x-name / ; Experimental type 611 iana-token) ; Other IANA registered type 612 ; 613 ; Default is BADGE 615 Description: This property parameter MAY be specified on "IMAGE" 616 properties. In the absence of this parameter, the value "BADGE" 617 MUST be used for the default behavior. The value determines how a 618 client ought to present an image supplied in iCalendar data to the 619 user. 621 Values for this parameter are registered with IANA as per 622 Section 8.3. New values can be added to this registry following 623 the procedure outlined in Section 8.2.1 of [RFC5545]. 625 Servers and clients MUST handle x-name and iana-token values they 626 don't recognize by not displaying any image at all. 628 Example: 630 IMAGE;VALUE=URI;DISPLAY=BADGE,THUMBNAIL;FMTTYPE=image/png:https://exa 631 mple.com/images/weather-cloudy.png 633 6.2. EMAIL Property Parameter 635 Parameter Name: EMAIL 637 Purpose: To specify an email address that is used to identify or 638 contact an organizer or attendee. 640 Format Definition: This property parameter is defined by the 641 following notation: 643 emailparam = "EMAIL" "=" param-value 645 Description: This property parameter MAY be specified on "ORGANIZER" 646 or "ATTENDEE" properties. This property can be used in situations 647 where the calendar user address value of "ORGANIZER" and 648 "ATTENDEE" properties is not likely to be an identifier that 649 recipients of scheduling messages could use to match the calendar 650 user with, for example, an address book entry. The value of this 651 property is an email address that can easily be matched by 652 recipients. Recipients can also use this value as an alternative 653 means of contacting the calendar user via email. If a recipient's 654 calendar user agent allows the recipient to save contact 655 information based on the "ORGANIZER" or "ATTENDEE" properties, 656 those calendar user agents SHOULD use any "EMAIL" property 657 parameter value for the email address of the contact over any 658 mailto: calendar user address specified as the value of the 659 property. Calendar user agents SHOULD NOT include an "EMAIL" 660 property parameter when its value matches the calendar user 661 address specified as the value of the property. 663 Example: 665 ATTENDEE;CN=Cyrus Daboo;EMAIL=cyrus@example.com:mailto:opaque-toke 666 n-1234@example.com 668 6.3. FEATURE Property Parameter 670 Parameter Name: FEATURE 672 Purpose: To specify a feature or features of a conference or 673 broadcast system. 675 Format Definition: This property parameter is defined by the 676 following notation: 678 featureparam = "FEATURE" "=" featuretext *("," featuretext) 679 featuretext = ("AUDIO" / ; Audio capability 680 "CHAT" / ; Chat or instant messaging 681 "FEED" / ; Blog or Atom feed 682 "MODERATOR" / ; Moderator dial-in code 683 "PHONE" / ; Phone conference 684 "SCREEN" / ; Screen sharing 685 "VIDEO" / ; Video capability 686 x-name / ; Experimental type 687 iana-token) ; Other IANA registered type 689 Description: This property parameter MAY be specified on the 690 "CONFERENCE" property. Multiple values can be specified. The 691 "MODERATOR" value is used to indicate that the property value is 692 specific to the owner/initiator of the conference and contains a 693 URI that "activates" the system (e.g., a "moderator" access code 694 for a phone conference system that is different from the "regular" 695 access code). 697 Example: 699 CONFERENCE;VALUE=URI;FEATURE=AUDIO:rtsp://audio.example.com/ 700 event 701 CONFERENCE;VALUE=URI;FEATURE=AUDIO,VIDEO:https://video-chat.exam 702 ple.com/;group-id=1234 704 6.4. LABEL Property Parameter 706 Parameter Name: LABEL 708 Purpose: To provide a human readable label. 710 Format Definition: This property parameter is defined by the 711 following notation: 713 labelparam = "LABEL" "=" param-value 715 Description: This property parameter MAY be specified on the 716 "CONFERENCE" property. It is anticipated that other extensions to 717 iCalendar will re-use this property parameter on new properties 718 that they define. As a result, clients SHOULD expect to find this 719 property parameter present on many different properties. It 720 provides a human readable label that can be presented to calendar 721 users to allow them to discriminate between properties which might 722 be similar, or provide additional information for properties that 723 are not self-describing. 725 Example: 727 CONFERENCE;VALUE=URI;FEATURE=VIDEO; 728 LABEL="Web video chat, access code=76543"; 729 :https://video-chat.example.com/;group-id=1234 731 7. Security Considerations 733 Several of the new properties or parameters defined by this 734 specification allow reference to "external" URIs. Care MUST be taken 735 when accessing data at external URIs as malicious content could be 736 present. In addition, access to those URIs could be tracked, leading 737 to loss of privacy. 739 The "CONFERENCE" property can include a "FEATURE" property parameter 740 with a "MODERATOR" value. In some cases the access code used by the 741 owner/initiator of a conference might be private to an individual and 742 clients and servers MUST ensure that such properties are not sent to 743 attendees of a scheduled component, or sharees of a shared component. 745 8. IANA Considerations 747 8.1. Property Registrations 749 This document defines the following new iCalendar properties to be 750 added to the registry defined in Section 8.2.3 of [RFC5545]: 752 +------------------+---------+--------------------------------------+ 753 | Property | Status | Reference | 754 +------------------+---------+--------------------------------------+ 755 | NAME | Current | RFCXXXX, Section 5.1 | 756 | DESCRIPTION | Current | RFC5545 Section 3.8.1.5, RFCXXXX, | 757 | | | Section 5.2 | 758 | UID | Current | RFC5545 Section 3.8.4.7, RFCXXXX, | 759 | | | Section 5.3 | 760 | LAST-MODIFIED | Current | RFC5545 Section 3.8.7.3, RFCXXXX, | 761 | | | Section 5.4 | 762 | URL | Current | RFC5545 Section 3.8.4.6, RFCXXXX, | 763 | | | Section 5.5 | 764 | CATEGORIES | Current | RFC5545 Section 3.8.1.2, RFCXXXX, | 765 | | | Section 5.6 | 766 | REFRESH-INTERVAL | Current | RFCXXXX, Section 5.7 | 767 | SOURCE | Current | RFCXXXX, Section 5.8 | 768 | COLOR | Current | RFCXXXX, Section 5.9 | 769 | IMAGE | Current | RFCXXXX, Section 5.10 | 770 | CONFERENCE | Current | RFCXXXX, Section 5.11 | 771 +------------------+---------+--------------------------------------+ 773 8.2. Parameter Registrations 775 This document defines the following new iCalendar property parameters 776 to be added to the registry defined in Section 8.2.4 of [RFC5545]: 778 +--------------------+---------+----------------------+ 779 | Property Parameter | Status | Reference | 780 +--------------------+---------+----------------------+ 781 | DISPLAY | Current | RFCXXXX, Section 6.1 | 782 | EMAIL | Current | RFCXXXX, Section 6.2 | 783 | FEATURE | Current | RFCXXXX, Section 6.3 | 784 | LABEL | Current | RFCXXXX, Section 6.4 | 785 +--------------------+---------+----------------------+ 787 8.3. Display Types Registry 789 This document defines the following new iCalendar value registry as 790 per Section 8.2.6 of [RFC5545]: 792 +--------------+---------+----------------------+ 793 | Display Type | Status | Reference | 794 +--------------+---------+----------------------+ 795 | BADGE | Current | RFCXXXX, Section 6.1 | 796 | GRAPHIC | Current | RFCXXXX, Section 6.1 | 797 | FULLSIZE | Current | RFCXXXX, Section 6.1 | 798 | THUMBNAIL | Current | RFCXXXX, Section 6.1 | 799 +--------------+---------+----------------------+ 801 8.4. Feature Types Registry 803 This document defines the following new iCalendar value registry as 804 per Section 8.2.6 of [RFC5545]: 806 +--------------+---------+----------------------+ 807 | Feature Type | Status | Reference | 808 +--------------+---------+----------------------+ 809 | AUDIO | Current | RFCXXXX, Section 6.3 | 810 | CHAT | Current | RFCXXXX, Section 6.3 | 811 | FEED | Current | RFCXXXX, Section 6.3 | 812 | MODERATOR | Current | RFCXXXX, Section 6.3 | 813 | PHONE | Current | RFCXXXX, Section 6.3 | 814 | SCREEN | Current | RFCXXXX, Section 6.3 | 815 | VIDEO | Current | RFCXXXX, Section 6.3 | 816 +--------------+---------+----------------------+ 818 9. Acknowledgments 820 Thanks to the following for feedback: Bernard Desruisseaux, Mike 821 Douglass, Lucia Fedorova, Ken Murchison, Arnaud Quillaud, and Dave 822 Thewlis. This specification came about via discussions at the 823 Calendaring and Scheduling Consortium. 825 10. References 827 10.1. Normative References 829 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 830 Requirement Levels", BCP 14, RFC 2119, 831 DOI 10.17487/RFC2119, March 1997, 832 . 834 [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax 835 Specifications: ABNF", STD 68, RFC 5234, 836 DOI 10.17487/RFC5234, January 2008, 837 . 839 [RFC5545] Desruisseaux, B., Ed., "Internet Calendaring and 840 Scheduling Core Object Specification (iCalendar)", 841 RFC 5545, DOI 10.17487/RFC5545, September 2009, 842 . 844 [W3C.REC-css3-color-20110607] 845 A‡elik, T., Lilley, C., and D. Baron, "CSS Color 846 Module Level 3", World Wide Web Consortium Recommendation 847 REC-css3-color-20110607, June 2011, 848 . 850 10.2. Informative References 852 [RFC2397] Masinter, L., "The "data" URL scheme", RFC 2397, 853 DOI 10.17487/RFC2397, August 1998, 854 . 856 [RFC3966] Schulzrinne, H., "The tel URI for Telephone Numbers", 857 RFC 3966, DOI 10.17487/RFC3966, December 2004, 858 . 860 [RFC5546] Daboo, C., Ed., "iCalendar Transport-Independent 861 Interoperability Protocol (iTIP)", RFC 5546, 862 DOI 10.17487/RFC5546, December 2009, 863 . 865 [RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer 866 Protocol (HTTP/1.1): Message Syntax and Routing", 867 RFC 7230, DOI 10.17487/RFC7230, June 2014, 868 . 870 Appendix A. Change History (To be removed by RFC Editor before 871 publication) 873 Changes in draft-ietf-calext-extensions-03: 875 1. AD: fixed =/ ABNF syntax. 877 2. AD: added description for CATEGORIES. 879 3. AD: Removed extra / in image ABNF. 881 4. AD: Fixed VALUE=URI in image ABNF. 883 5. AD: Mention https in addition to http. Changed all examples to 884 use https: 886 6. AD: fixed DISPLAY ABNF syntax. 888 Changes in draft-ietf-calext-extensions-02: 890 1. Refresh expired draft - no changes. 892 Changes in draft-ietf-calext-extensions-01: 894 1. Clarified difference between SOURCE and URL properties. 896 2. Use labelparam not infoparam. 898 Changes in draft-ietf-calext-extensions-00: 900 1. Document renamed after WG adoption. 902 2. Fixed tel: URI reference. 904 Changes in draft-daboo-icalendar-extensions-09: 906 1. Re-instated a trimmed down version of the CONFERENCE property 907 after serious interest expressed by implementors. 909 2. LABEL property used instead of INFO - appropriated from another 910 iCalendar draft. 912 Changes in draft-daboo-icalendar-extensions-08: 914 1. Trimmed down the display values to a minimal set. 916 Changes in draft-daboo-icalendar-extensions-07: 918 1. Removed ALTURI parameter - now use ALTREP. 920 2. Removed VALID property. 922 3. Removed TIMEZONE-ID property. 924 4. Added FULLSIZE and THUMBNAIL display values. 926 5. Added EMAIL property parameter. 928 6. Added LAST-MODIFIED property for use with VCALENDAR. 930 7. Added CATEGORIES property for use with VCALENDAR. 932 8. URL use now aligned with 5545. 934 9. Added SOURCE property. 936 10. COLOR now uses CSS3 values. 938 Changes in draft-daboo-icalendar-extensions-06: 940 1. Removed BROADCAST/CONFERENCE properties and related parameters. 942 Changes in draft-daboo-icalendar-extensions-05: 944 1. Added section with recommendation on handling extension 945 properties. 947 2. Added VALID property. 949 Changes in draft-daboo-icalendar-extensions-04: 951 1. TZID changed to new property TIMEZONE-ID. 953 2. Minor formal syntax changes. 955 Changes in draft-daboo-icalendar-extensions-03: 957 1. Dropped CALENDAR- prefix 959 2. DESCRIPTION, UID and TZID now based on existing RFC5545 960 properties 962 3. COLOR now on both the calendar and component level 964 4. IMAGE now on both the calendar and component level 966 5. Added FEATURE and REGION parameters to CONFERENCE property 968 6. Added ALTURI parameter to IMAGE property 970 7. Added FEED value to FEATURE parameter 972 8. Added BROADCAST property and clarified that CONFERENCE is for bi- 973 direction channels and BROADCAST is for uni-directional. 975 Changes in draft-daboo-icalendar-extensions-02: 977 1. Minor wording changes. 979 2. Interval is now described as the "minimum interval". 981 3. Added CONFERENCE property and INFO parameter. 983 Changes in draft-daboo-icalendar-extensions-01: 985 1. Fixed DISPLAY parameter handling of x- and iana tokens to state 986 that clients ignore the image if the token is not recognized. 988 2. Allow language variants for CALENDAR-NAME and CALENDAR- 989 DESCRIPTION. 991 3. Added registry for DISPLAY values. 993 Author's Address 995 Cyrus Daboo 996 Apple Inc. 997 1 Infinite Loop 998 Cupertino, CA 95014 999 USA 1001 Email: cyrus@daboo.name 1002 URI: http://www.apple.com/