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Daboo 3 Internet-Draft Apple Inc. 4 Updates: 5545 (if approved) March 16, 2014 5 Intended status: Standards Track 6 Expires: September 17, 2014 8 New Properties for iCalendar 9 draft-daboo-icalendar-extensions-08 11 Abstract 13 This document defines a set of new properties for iCalendar data as 14 well as extending the use of some existing properties to the entire 15 iCalendar object. 17 Status of this Memo 19 This Internet-Draft is submitted in full conformance with the 20 provisions of BCP 78 and BCP 79. 22 Internet-Drafts are working documents of the Internet Engineering 23 Task Force (IETF). Note that other groups may also distribute 24 working documents as Internet-Drafts. The list of current Internet- 25 Drafts is at http://datatracker.ietf.org/drafts/current/. 27 Internet-Drafts are draft documents valid for a maximum of six months 28 and may be updated, replaced, or obsoleted by other documents at any 29 time. It is inappropriate to use Internet-Drafts as reference 30 material or to cite them other than as "work in progress." 32 This Internet-Draft will expire on September 17, 2014. 34 Copyright Notice 36 Copyright (c) 2014 IETF Trust and the persons identified as the 37 document authors. All rights reserved. 39 This document is subject to BCP 78 and the IETF Trust's Legal 40 Provisions Relating to IETF Documents 41 (http://trustee.ietf.org/license-info) in effect on the date of 42 publication of this document. Please review these documents 43 carefully, as they describe your rights and restrictions with respect 44 to this document. Code Components extracted from this document must 45 include Simplified BSD License text as described in Section 4.e of 46 the Trust Legal Provisions and are provided without warranty as 47 described in the Simplified BSD License. 49 Table of Contents 51 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 52 2. Conventions Used in This Document . . . . . . . . . . . . . . 3 53 3. Backwards Compatible Extension Properties . . . . . . . . . . 3 54 4. Modifications to Calendar Components . . . . . . . . . . . . . 4 55 5. Properties . . . . . . . . . . . . . . . . . . . . . . . . . . 5 56 5.1. NAME Property . . . . . . . . . . . . . . . . . . . . . . 5 57 5.2. DESCRIPTION Property . . . . . . . . . . . . . . . . . . . 6 58 5.3. UID Property . . . . . . . . . . . . . . . . . . . . . . . 6 59 5.4. LAST-MODIFIED Property . . . . . . . . . . . . . . . . . . 7 60 5.5. URL Property . . . . . . . . . . . . . . . . . . . . . . . 7 61 5.6. CATEGORIES Property . . . . . . . . . . . . . . . . . . . 7 62 5.7. REFRESH-INTERVAL Property . . . . . . . . . . . . . . . . 8 63 5.8. SOURCE Property . . . . . . . . . . . . . . . . . . . . . 9 64 5.9. COLOR Property . . . . . . . . . . . . . . . . . . . . . . 9 65 5.10. IMAGE Property . . . . . . . . . . . . . . . . . . . . . . 10 66 6. Property Parameters . . . . . . . . . . . . . . . . . . . . . 12 67 6.1. DISPLAY Property Parameter . . . . . . . . . . . . . . . . 12 68 6.2. EMAIL Property Parameter . . . . . . . . . . . . . . . . . 13 69 7. Security Considerations . . . . . . . . . . . . . . . . . . . 13 70 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 71 8.1. Property Registrations . . . . . . . . . . . . . . . . . . 14 72 8.2. Parameter Registrations . . . . . . . . . . . . . . . . . 14 73 8.3. Display Types Registry . . . . . . . . . . . . . . . . . . 14 74 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 15 75 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 76 10.1. Normative References . . . . . . . . . . . . . . . . . . . 15 77 10.2. Informative References . . . . . . . . . . . . . . . . . . 15 78 Appendix A. Change History (To be removed by RFC Editor 79 before publication) . . . . . . . . . . . . . . . . . 15 80 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 17 82 1. Introduction 84 The iCalendar [RFC5545] data format is used to represent calendar 85 data and is used with iTIP [RFC5546] to handle scheduling operations 86 between calendar users. iCalendar is in widespread use, and in 87 accordance with provisions in that specification, extension elements 88 have been added by various vendors to the data format in order to 89 support and enhance capabilities. This specification collects a 90 number of these ad-hoc extensions and uses the new IANA registry 91 capability defined in [RFC5545] to register standard variants with 92 clearly defined definitions and semantics. In addition, some new 93 elements are introduced for features that vendors have recently been 94 requesting. 96 2. Conventions Used in This Document 98 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 99 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 100 "OPTIONAL" in this document are to be interpreted as described in 101 [RFC2119]. 103 The notation used in this memo is the ABNF notation of [RFC5234] as 104 used by iCalendar [RFC5545]. Any syntax elements shown below that 105 are not explicitly defined in this specification come from iCalendar 106 [RFC5545]. 108 3. Backwards Compatible Extension Properties 110 iCalendar defines properties which can have different value types 111 indicated by a "VALUE" parameter. The definition of a property 112 specifies a "default" value type that is assumed to be used when no 113 "VALUE" parameter is present. However, this poses a problem to 114 iCalendar parser/generator software that does not know about the 115 default values for new properties. For example, if a new property 116 "FOO" were defined with a default value type of URI, and a URI value 117 with a comma was used, an iCalendar generator not aware of this fact 118 would likely treat the property value as "TEXT" and apply backslash 119 escaping to the comma in the value, effectively making it an invalid 120 URI value. 122 To avoid this problem, this specification recommends that all 123 properties not defined in [RFC5545], always include a "VALUE" 124 parameter, if the type is other than "TEXT". i.e., in the example 125 above, the "FOO" property would have a "VALUE=URI" parameter. This 126 allows iCalendar parser/generator software to track the correct types 127 of unknown properties. 129 New properties defined in this specification use the term "no 130 default" in the "Value Type" definition to indicate that the "VALUE" 131 parameter has to be included. 133 4. Modifications to Calendar Components 135 The following changes to the syntax defined in iCalendar [RFC5545] 136 are made here. New elements are defined in subsequent sections. 138 calprops /= *( 139 ; 140 ; The following are OPTIONAL, 141 ; but MUST NOT occur more than once. 142 ; 143 uid / last-mod / url / 144 refresh / source / color 145 ; 146 ; The following are OPTIONAL, 147 ; and MAY occur more than once. 148 ; 149 name / description / categories / 150 image 151 ; 152 ) 154 eventprop /= *( 155 ; 156 ; The following are OPTIONAL, 157 ; but MUST NOT occur more than once. 158 ; 159 color / 160 ; 161 ; The following are OPTIONAL, 162 ; and MAY occur more than once. 163 ; 164 image 165 ; 166 ) 168 todoprop /= *( 169 ; 170 ; The following are OPTIONAL, 171 ; but MUST NOT occur more than once. 172 ; 173 color / 174 ; 175 ; The following are OPTIONAL, 176 ; and MAY occur more than once. 177 ; 178 image 179 ; 180 ) 182 jourprop /= *( 183 ; 184 ; The following are OPTIONAL, 185 ; but MUST NOT occur more than once. 186 ; 187 color / 188 ; 189 ; The following are OPTIONAL, 190 ; and MAY occur more than once. 191 ; 192 image 193 ; 194 ) 196 5. Properties 198 5.1. NAME Property 200 Property Name: NAME 202 Purpose: This property specifies the name of the calendar. 204 Value Type: TEXT 206 Property Parameters: IANA, non-standard, alternate text 207 representation, and language property parameters can be specified 208 on this property. 210 Conformance: This property can be specified multiple times in an 211 iCalendar object. However, each property MUST represent the name 212 of the calendar in a different language. 214 Description: This property is used to specify a name of the 215 iCalendar object that can be used by calendar user agents when 216 presenting the calendar data to a user. Whilst a calendar only 217 has a single name, multiple language variants can be specified by 218 including this property multiple times with different "LANGUAGE" 219 parameter values on each. 221 Format Definition: This property is defined by the following 222 notation: 224 name = "NAME" nameparam ":" text CRLF 226 nameparam = *( 227 ; 228 ; The following are OPTIONAL, 229 ; but MUST NOT occur more than once. 230 ; 231 (";" altrepparam) / (";" languageparam) / 232 ; 233 ; The following is OPTIONAL, 234 ; and MAY occur more than once. 235 ; 236 (";" other-param) 237 ; 238 ) 240 Example: The following is an example of this property: 242 NAME:Company Vacation Days 244 5.2. DESCRIPTION Property 246 This specification modifies the definition of the "DESCRIPTION" 247 property to allow it to be defined on an iCalendar object. The 248 following additions are made to the definition of this property. 250 Purpose: This property specifies the description of the calendar. 252 Conformance: This property can be specified multiple times in an 253 iCalendar object. However, each property MUST represent the 254 description of the calendar in a different language. 256 Description: This property is used to specify a lengthy textual 257 description of the iCalendar object that can be used by calendar 258 user agents when describing the nature of the calendar data to a 259 user. Whilst a calendar only has a single description, multiple 260 language variants can be specified by including this property 261 multiple times with different "LANGUAGE" parameter values on each. 263 5.3. UID Property 265 This specification modifies the definition of the "UID" property to 266 allow it to be defined on an iCalendar object. The following 267 additions are made to the definition of this property. 269 Purpose: This property specifies the persistent, globally unique 270 identifier for the iCalendar object. This can be used, for 271 example, to identify duplicate calendar streams that a client may 272 have been given access to. It can be used in conjunction with the 273 "LAST-MODIFIED" property also specified on the "VCALENDAR" object, 274 to identify the most recent version of a calendar. 276 Conformance: This property can be specified once in an iCalendar 277 object. 279 5.4. LAST-MODIFIED Property 281 This specification modifies the definition of the "LAST-MODIFIED" 282 property to allow it to be defined on an iCalendar object. The 283 following additions are made to the definition of this property. 285 Purpose: This property specifies the date and time that the 286 information associated with the calendar was last revised. 288 Conformance: This property can be specified once in an iCalendar 289 object. 291 5.5. URL Property 293 This specification modifies the definition of the "URL" property to 294 allow it to be defined on an iCalendar object. The following 295 additions are made to the definition of this property. 297 Purpose: This property may be used to convey a location where a more 298 dynamic rendition of the calendar information can be found. 300 Conformance: This property can be specified once in an iCalendar 301 object. 303 5.6. CATEGORIES Property 305 This specification modifies the definition of the "CATEGORIES" 306 property to allow it to be defined on an iCalendar object. The 307 following additions are made to the definition of this property. 309 Purpose: This property defines the categories for an entire 310 calendar. 312 Conformance: This property can be specified multiple times in an 313 iCalendar object. 315 5.7. REFRESH-INTERVAL Property 317 Property Name: REFRESH-INTERVAL 319 Purpose: This property specifies a suggested minimum interval for 320 polling for changes of the calendar data from the original source 321 of that data. 323 Value Type: DURATION - no default 325 Property Parameters: IANA and non-standard property parameters can 326 be specified on this property. 328 Conformance: This property can be specified once in an iCalendar 329 object. 331 Description: This property specifies a positive duration that gives 332 a suggested minimum polling interval for checking for updates to 333 the calendar data. The value of this property SHOULD be used by 334 calendar user agents to limit the polling interval for calendar 335 data updates to the minimum interval specified. 337 Format Definition: This property is defined by the following 338 notation: 340 refresh = "REFRESH-INTERVAL" refreshparam 341 ":" dur-value CRLF 342 ;consisting of a positive duration of time. 344 refreshparam = *( 345 ; 346 ; The following is REQUIRED, 347 ; but MUST NOT occur more than once. 348 ; 349 (";" "VALUE" "=" "DURATION") / 350 ; 351 ; The following is OPTIONAL, 352 ; and MAY occur more than once. 353 ; 354 (";" other-param) 355 ; 356 ) 358 Example: The following is an example of this property: 360 REFRESH-INTERVAL;VALUE=DURATION:P1W 362 5.8. SOURCE Property 364 Property Name: SOURCE 366 Purpose: This property identified a URI where calendar data can be 367 refreshed from. 369 Value Type: URI 371 Property Parameters: IANA and non-standard property parameters can 372 be specified on this property. 374 Conformance: This property can be specified once in an iCalendar 375 object. 377 Description: This property identifies a location where a client can 378 retrieve updated data for the calendar. Clients SHOULD honor any 379 specified "REFRESH-INTERVAL" value when periodically retrieving 380 data. 382 Format Definition: This property is defined by the following 383 notation: 385 source = "SOURCE" sourceparam ":" uri CRLF 387 sourceparam = *(";" other-param) 389 Example: The following is an example of this property: 391 SOURCE:http://example.com/holidays.ics 393 5.9. COLOR Property 395 Property Name: COLOR 397 Purpose: This property specifies a color used for displaying the 398 calendar, event, todo, or journal data. 400 Value Type: TEXT 402 Property Parameters: IANA and non-standard property parameters can 403 be specified on this property. 405 Conformance: This property can be specified once in an iCalendar 406 object, or "VEVENT", "VTODO", or "VJOURNAL" calendar components. 408 Description: This property specifies a color that clients MAY use 409 when presenting the relevant data to a user. Typically this would 410 appear as the "background" color of events or tasks. The value is 411 a case-insensitive color name taken from the CSS3 set of names, 412 defined in Section 4.3 of [W3C.REC-css3-color-20110607]. 414 Format Definition: This property is defined by the following 415 notation: 417 color = "COLOR" colorparam ":" text CRLF 418 ; Value is CSS3 color name 420 colorparam = *(";" other-param) 422 Example: The following is an example of this property: 424 COLOR:turquoise 426 5.10. IMAGE Property 428 Property Name: IMAGE 430 Purpose: This property specifies an image associated with the 431 calendar or a calendar component. 433 Value Type: URI or BINARY - no default. The value MUST refer to or 434 be data with a media type of "image". 436 Property Parameters: IANA, non-standard, display, inline encoding, 437 and value data type property parameters can be specified on this 438 property. The format type parameter can be specified on this 439 property and is RECOMMENDED for inline binary encoded content 440 information. 442 Conformance: This property can be specified multiple times in an 443 iCalendar object, or "VEVENT", "VTODO", or "VJOURNAL" calendar 444 components. 446 Description: This property specifies an image for an iCalendar 447 object or a calendar component via a uri or directly with inline 448 data that can be used by calendar user agents when presenting the 449 calendar data to a user. Multiple properties MAY be used to 450 specify alternative sets of images with, for example, varying 451 media subtypes, resolutions or sizes. When multiple properties 452 are present, calendar user agents SHOULD display only one of them, 453 picking one that provides the most appropriate image quality, or 454 display none. The "DISPLAY" parameter is used to indicate the 455 intended display mode for the image. The "ALTREP" parameter, 456 defined in [RFC5545], can be used to provide a "clickable" image 457 where the URI in the parameter value can be "launched" by a click 458 on the image in the calendar user agent. 460 Format Definition: This property is defined by the following 461 notation: 463 image = "IMAGE" imageparam ( ":" uri ) / 464 ( 465 ";" "ENCODING" "=" "BASE64" 466 ";" "VALUE" "=" "BINARY" 467 ":" binary 468 ) / 469 CRLF 471 imageparam = *( 472 ; 473 ; The following is REQUIRED, 474 ; but MUST NOT occur more than once. 475 ; 476 (";" "VALUE" "=" "URI") / 477 ; 478 ; The following is OPTIONAL for a URI value, 479 ; RECOMMENDED for a BINARY value, 480 ; and MUST NOT occur more than once. 481 ; 482 (";" fmttypeparam) / 483 ; 484 ; The following are OPTIONAL, 485 ; and MUST NOT occur more than once. 486 ; 487 (";" altrepparam) / (";" displayparam) / 488 ; 489 ; The following is OPTIONAL, 490 ; and MAY occur more than once. 491 ; 492 (";" other-param) 493 ; 494 ) 496 Example: The following is an example of this property: 498 IMAGE;VALUE=URI;DISPLAY=BADGE;FMTTYPE=image/png:h 499 ttp://example.com/images/party.png 501 6. Property Parameters 503 6.1. DISPLAY Property Parameter 505 Parameter Name: DISPLAY 507 Purpose: To specify different ways in which an image for a calendar 508 or component can be displayed. 510 Format Definition: This property parameter is defined by the 511 following notation: 513 displayparam = "DISPLAY" "=" displayval *("," displayval) 515 displayval = ("BADGE" / ; image inline with the title of the event 516 "GRAPHIC" / ; a full image replacement for the event 517 ; itself 518 "FULLSIZE / ; an image that is used to enhance the 519 ; event 520 "THUMBNAIL / ; a smaller variant of "FULLSIZE" to be 521 ; used when space for the image is 522 ; constrained 523 x-name / ; Experimental type 524 iana-token) ; Other IANA registered type 525 ; 526 ; Default is BADGE 528 Description: This property parameter MAY be specified on "IMAGE" 529 properties. In the absence of this parameter, the value "BADGE" 530 MUST be used for the default behavior. The value determines how a 531 client ought to present an image supplied in iCalendar data to the 532 user. 534 Values for this parameter are registered with IANA as per 535 Section 8.3. New values can be added to this registry following 536 the procedure outlined in Section 8.2.1 of [RFC5545]. 538 Servers and clients MUST handle x-name and iana-token values they 539 don't recognize by not displaying any image at all. 541 Example: 543 IMAGE;VALUE=URI;DISPLAY=BADGE,THUMBNAIL,;FMTTYPE=image/png:http://exa 544 mple.com/images/weather-cloudy.png 546 6.2. EMAIL Property Parameter 548 Parameter Name: EMAIL 550 Purpose: To specify an email address that is used to identify or 551 contact an organizer or attendee. 553 Format Definition: This property parameter is defined by the 554 following notation: 556 emailparam = "EMAIL" "=" param-value 558 Description: This property parameter MAY be specified on "ORGANIZER" 559 or "ATTENDEE" properties. This property can be used in situations 560 where the calendar user address value of "ORGANIZER" and 561 "ATTENDEE" properties is not likely to be an identifier that 562 recipients of scheduling messages could use to match the calendar 563 user with, for example, an address book entry. The value of this 564 property is an email address that can easily be matched by 565 recipients. Recipients can also use this value as an alternative 566 means of contacting the calendar user via email. If a recipient's 567 calendar user agent allows the recipient to save contact 568 information based on the "ORGANIZER" or "ATTENDEE" properties, 569 those calendar user agents SHOULD use any "EMAIL" property 570 parameter value for the email address of the contact over any 571 mailto: calendar user address specified as the value of the 572 property. Calendar user agents SHOULD NOT include an "EMAIL" 573 property parameter when its value matches the calendar user 574 address specified as the value of the property. 576 Example: 578 ATTENDEE;CN=Cyrus Daboo;EMAIL=cyrus@example.com:mailto:opaque-toke 579 n-1234@example.com 581 7. Security Considerations 583 Several of the new properties or parameters defined by this 584 specification allow reference to "external" URIs. Care MUST be taken 585 when accessing data at external URIs as malicious content could be 586 present. In addition, access to those URIs could be tracked, leading 587 to loss of privacy. 589 8. IANA Considerations 590 8.1. Property Registrations 592 This document defines the following new iCalendar properties to be 593 added to the registry defined in Section 8.2.3 of [RFC5545]: 595 +------------------+---------+--------------------------------------+ 596 | Property | Status | Reference | 597 +------------------+---------+--------------------------------------+ 598 | NAME | Current | RFCXXXX, Section 5.1 | 599 | DESCRIPTION | Current | RFC5545 Section 3.8.1.5, RFCXXXX, | 600 | | | Section 5.2 | 601 | UID | Current | RFC5545 Section 3.8.4.7, RFCXXXX, | 602 | | | Section 5.3 | 603 | LAST-MODIFIED | Current | RFC5545 Section 3.8.7.3, RFCXXXX, | 604 | | | Section 5.4 | 605 | URL | Current | RFC5545 Section 3.8.4.6, RFCXXXX, | 606 | | | Section 5.5 | 607 | CATEGORIES | Current | RFC5545 Section 3.8.1.2, RFCXXXX, | 608 | | | Section 5.6 | 609 | REFRESH-INTERVAL | Current | RFCXXXX, Section 5.7 | 610 | SOURCE | Current | RFCXXXX, Section 5.8 | 611 | COLOR | Current | RFCXXXX, Section 5.9 | 612 | IMAGE | Current | RFCXXXX, Section 5.10 | 613 +------------------+---------+--------------------------------------+ 615 8.2. Parameter Registrations 617 This document defines the following new iCalendar property parameters 618 to be added to the registry defined in Section 8.2.4 of [RFC5545]: 620 +--------------------+---------+----------------------+ 621 | Property Parameter | Status | Reference | 622 +--------------------+---------+----------------------+ 623 | DISPLAY | Current | RFCXXXX, Section 6.1 | 624 | EMAIL | Current | RFCXXXX, Section 6.2 | 625 +--------------------+---------+----------------------+ 627 8.3. Display Types Registry 629 This document defines the following new iCalendar value registry as 630 per Section 8.2.6 of [RFC5545]: 632 +--------------+---------+----------------------+ 633 | Display Type | Status | Reference | 634 +--------------+---------+----------------------+ 635 | BADGE | Current | RFCXXXX, Section 6.1 | 636 | GRAPHIC | Current | RFCXXXX, Section 6.1 | 637 | FULLSIZE | Current | RFCXXXX, Section 6.1 | 638 | THUMBNAIL | Current | RFCXXXX, Section 6.1 | 639 +--------------+---------+----------------------+ 641 9. Acknowledgments 643 Thanks to the following for feedback: Bernard Desruisseaux, Mike 644 Douglass, Arnaud Quillaud, and Dave Thewlis. This specification came 645 about via discussions at the Calendaring and Scheduling Consortium. 647 10. References 649 10.1. Normative References 651 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 652 Requirement Levels", BCP 14, RFC 2119, March 1997. 654 [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax 655 Specifications: ABNF", STD 68, RFC 5234, January 2008. 657 [RFC5545] Desruisseaux, B., "Internet Calendaring and Scheduling 658 Core Object Specification (iCalendar)", RFC 5545, 659 September 2009. 661 [W3C.REC-css3-color-20110607] 662 Celik, T., Lilley, C., and D. Baron, "CSS Color Module 663 Level 3", World Wide Web Consortium Recommendation REC- 664 css3-color-20110607, June 2011, 665 . 667 10.2. Informative References 669 [RFC5546] Daboo, C., "iCalendar Transport-Independent 670 Interoperability Protocol (iTIP)", RFC 5546, 671 December 2009. 673 Appendix A. Change History (To be removed by RFC Editor before 674 publication) 676 Changes in -08: 678 1. Trimmed down the display values to a minimal set. 680 Changes in -07: 682 1. Removed ALTURI parameter - now use ALTREP. 684 2. Removed VALID property. 686 3. Removed TIMEZONE-ID property. 688 4. Added FULLSIZE and THUMBNAIL display values. 690 5. Added EMAIL property parameter. 692 6. Added LAST-MODIFIED property for use with VCALENDAR. 694 7. Added CATEGORIES property for use with VCALENDAR. 696 8. URL use now aligned with 5545. 698 9. Added SOURCE property. 700 10. COLOR now uses CSS3 values. 702 Changes in -06: 704 1. Removed BROADCAST/CONFERENCE properties and related parameters. 706 Changes in -05: 708 1. Added section with recommendation on handling extension 709 properties. 711 2. Added VALID property. 713 Changes in -04: 715 1. TZID changed to new property TIMEZONE-ID. 717 2. Minor formal syntax changes. 719 Changes in -03: 721 1. Dropped CALENDAR- prefix 723 2. DESCRIPTION, UID and TZID now based on existing RFC5545 724 properties 726 3. COLOR now on both the calendar and component level 728 4. IMAGE now on both the calendar and component level 730 5. Added FEATURE and REGION parameters to CONFERENCE property 732 6. Added ALTURI parameter to IMAGE property 734 7. Added FEED value to FEATURE parameter 736 8. Added BROADCAST property and clarified that CONFERENCE is for bi- 737 direction channels and BROADCAST is for uni-directional. 739 Changes in -02: 741 1. Minor wording changes. 743 2. Interval is now described as the "minimum interval". 745 3. Added CONFERENCE property and INFO parameter. 747 Changes in -01: 749 1. Fixed DISPLAY parameter handling of x- and iana tokens to state 750 that clients ignore the image if the token is not recognized. 752 2. Allow language variants for CALENDAR-NAME and CALENDAR- 753 DESCRIPTION. 755 3. Added registry for DISPLAY values. 757 Author's Address 759 Cyrus Daboo 760 Apple Inc. 761 1 Infinite Loop 762 Cupertino, CA 95014 763 USA 765 Email: cyrus@daboo.name 766 URI: http://www.apple.com/