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Calendaring Extensions                                            R. Tse
Internet-Draft                                                    P. Tam
Updates: 5545, 6321, 6350, 6351, 7953,                            Ribose
         7265, 7095 (if approved)                           K. Murchison
Intended status: Standards Track                        FastMail Pty Ltd
Expires: December 10, 2018                                   M. Douglass
                                                     Spherical Cow Group
                                                            June 8, 2018


                  The vObject Model and vFormat Syntax
                  draft-calconnect-vobject-vformat-04

Abstract

   This document specifies the vObject data model and its corresponding
   syntax vFormat.

   vObject represents the generalized data model, and vFormat the
   generalized data format, of the following specifications and fully
   covers them:

   o  RFC 6350, vCard version 4.0: the VCARD component;

   o  RFC 5545, Internet Calendaring and Scheduling Core Object
      Specification (iCalendar): the VCALENDAR, VEVENT, VJOURNAL,
      VFREEBUSY, VTIMEZONE, VALARM, VTODO, STANDARD and DAYLIGHT
      components;

   o  RFC 7953, Calendar Availability Extensions: the VAVAILABILITY and
      AVAILABLE components;

   o  I-Ddaboo-icalendar-vpatch, iCalendar Patching: the VPATCH
      component; and

   o  alternative formats for iCalendar and vCard, including RFC 6321,
      xCal; RFC 7265, jCal; RFC 6351, xCard; and RFC 7095, jCard.

   This work is produced by the CalConnect TC-VCARD and TC-CALENDAR
   committees.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute



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   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on December 10, 2018.

Copyright Notice

   Copyright (c) 2018 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   8
   2.  Terms and Definitions . . . . . . . . . . . . . . . . . . . .   8
     2.1.  Definitions . . . . . . . . . . . . . . . . . . . . . . .   9
   3.  vObject Data Model  . . . . . . . . . . . . . . . . . . . . .   9
     3.1.  vObject-compliant Models  . . . . . . . . . . . . . . . .  10
     3.2.  Elements  . . . . . . . . . . . . . . . . . . . . . . . .  10
       3.2.1.  Equivalence . . . . . . . . . . . . . . . . . . . . .  11
     3.3.  Component . . . . . . . . . . . . . . . . . . . . . . . .  11
       3.3.1.  Uniqueness Identifying Property . . . . . . . . . . .  12
       3.3.2.  Normalizing A Component . . . . . . . . . . . . . . .  13
         3.3.2.1.  Sorted Component Properties . . . . . . . . . . .  13
         3.3.2.2.  Sorted Inner Components . . . . . . . . . . . . .  13
         3.3.2.3.  Normalized Inner Components . . . . . . . . . . .  13
       3.3.3.  vObject Property  . . . . . . . . . . . . . . . . . .  13
         3.3.3.1.  Normalized Values . . . . . . . . . . . . . . . .  14
         3.3.3.2.  Normalized Parameters . . . . . . . . . . . . . .  14
       3.3.4.  Property Value  . . . . . . . . . . . . . . . . . . .  14
       3.3.5.  Normalization Of Property Values  . . . . . . . . . .  14
       3.3.6.  Property Parameter  . . . . . . . . . . . . . . . . .  14
         3.3.6.1.  Value Lists . . . . . . . . . . . . . . . . . . .  15
       3.3.7.  Default Property Parameter Values . . . . . . . . . .  15



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       3.3.8.  Property Parameter Value  . . . . . . . . . . . . . .  15
       3.3.9.  Normalizing Multiple Parameter Values . . . . . . . .  15
       3.3.10. Property Group  . . . . . . . . . . . . . . . . . . .  16
   4.  vFormat Syntax  . . . . . . . . . . . . . . . . . . . . . . .  16
     4.1.  ABNF Format Definition  . . . . . . . . . . . . . . . . .  16
     4.2.  Component . . . . . . . . . . . . . . . . . . . . . . . .  18
       4.2.1.  Component Name In Uppercase . . . . . . . . . . . . .  18
       4.2.2.  Order Of Inner Components And Properties  . . . . . .  18
       4.2.3.  Maintain Validity . . . . . . . . . . . . . . . . . .  18
     4.3.  Property  . . . . . . . . . . . . . . . . . . . . . . . .  19
       4.3.1.  Uppercased Property Name  . . . . . . . . . . . . . .  19
       4.3.2.  Normalized Parameters . . . . . . . . . . . . . . . .  19
       4.3.3.  Wrapped Content Line  . . . . . . . . . . . . . . . .  19
     4.4.  Property Value  . . . . . . . . . . . . . . . . . . . . .  19
       4.4.1.  Normalizing Property Values . . . . . . . . . . . . .  20
     4.5.  Property Parameter  . . . . . . . . . . . . . . . . . . .  20
       4.5.1.  Multiple Property Parameters  . . . . . . . . . . . .  20
       4.5.2.  Expanded Form Of Property Parameter Value List  . . .  20
       4.5.3.  Uppercased Property Parameter Names . . . . . . . . .  20
       4.5.4.  Join Identical Property Parameter Names . . . . . . .  21
       4.5.5.  Express Default Property Value Types  . . . . . . . .  21
     4.6.  Property Parameter Value  . . . . . . . . . . . . . . . .  21
       4.6.1.  Format Definition . . . . . . . . . . . . . . . . . .  22
       4.6.2.  Description . . . . . . . . . . . . . . . . . . . . .  22
       4.6.3.  Example . . . . . . . . . . . . . . . . . . . . . . .  23
       4.6.4.  Normalization of Line Breaks  . . . . . . . . . . . .  23
       4.6.5.  Normalizing Parameter Values Via DQOUTE Wrapping  . .  23
     4.7.  Property Group  . . . . . . . . . . . . . . . . . . . . .  23
   5.  vObject Value Types And Notation Syntax . . . . . . . . . . .  23
     5.1.  Value Type Notation . . . . . . . . . . . . . . . . . . .  24
     5.2.  Meta Value Types  . . . . . . . . . . . . . . . . . . . .  24
       5.2.1.  FIELDSET  . . . . . . . . . . . . . . . . . . . . . .  24
         5.2.1.1.  Value Type Notation . . . . . . . . . . . . . . .  24
         5.2.1.2.  Example 1 . . . . . . . . . . . . . . . . . . . .  24
         5.2.1.3.  Example 2 . . . . . . . . . . . . . . . . . . . .  25
         5.2.1.4.  Normalizing a FIELDSET  . . . . . . . . . . . . .  25
       5.2.2.  LIST  . . . . . . . . . . . . . . . . . . . . . . . .  25
         5.2.2.1.  Value Type Notation . . . . . . . . . . . . . . .  25
         5.2.2.2.  Example 1 . . . . . . . . . . . . . . . . . . . .  25
         5.2.2.3.  Example 2 . . . . . . . . . . . . . . . . . . . .  26
         5.2.2.4.  Normalizing a LIST  . . . . . . . . . . . . . . .  26
       5.2.3.  MAP . . . . . . . . . . . . . . . . . . . . . . . . .  26
         5.2.3.1.  Value Type Notation . . . . . . . . . . . . . . .  26
         5.2.3.2.  Example . . . . . . . . . . . . . . . . . . . . .  26
         5.2.3.3.  Normalizing a MAP . . . . . . . . . . . . . . . .  27
     5.3.  Basic Value Types . . . . . . . . . . . . . . . . . . . .  27
       5.3.1.  TEXT  . . . . . . . . . . . . . . . . . . . . . . . .  27
         5.3.1.1.  Value Type Notation . . . . . . . . . . . . . . .  27



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         5.3.1.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  27
         5.3.1.3.  Format Definition . . . . . . . . . . . . . . . .  27
         5.3.1.4.  Associated parameters . . . . . . . . . . . . . .  27
         5.3.1.5.  Example . . . . . . . . . . . . . . . . . . . . .  28
       5.3.2.  URI . . . . . . . . . . . . . . . . . . . . . . . . .  28
         5.3.2.1.  Value Type Notation . . . . . . . . . . . . . . .  28
         5.3.2.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  28
         5.3.2.3.  Format Definition . . . . . . . . . . . . . . . .  28
         5.3.2.4.  Description . . . . . . . . . . . . . . . . . . .  28
         5.3.2.5.  Example . . . . . . . . . . . . . . . . . . . . .  28
         5.3.2.6.  Normalization . . . . . . . . . . . . . . . . . .  29
       5.3.3.  BOOLEAN . . . . . . . . . . . . . . . . . . . . . . .  29
         5.3.3.1.  Value Type Notation . . . . . . . . . . . . . . .  29
         5.3.3.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  29
         5.3.3.3.  Format Definition . . . . . . . . . . . . . . . .  29
         5.3.3.4.  Description . . . . . . . . . . . . . . . . . . .  29
         5.3.3.5.  Examples  . . . . . . . . . . . . . . . . . . . .  29
         5.3.3.6.  Normalization . . . . . . . . . . . . . . . . . .  29
       5.3.4.  INTEGER . . . . . . . . . . . . . . . . . . . . . . .  29
         5.3.4.1.  Value Type Notation . . . . . . . . . . . . . . .  30
         5.3.4.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  30
         5.3.4.3.  Format Definition . . . . . . . . . . . . . . . .  30
         5.3.4.4.  Description . . . . . . . . . . . . . . . . . . .  30
         5.3.4.5.  Examples  . . . . . . . . . . . . . . . . . . . .  30
         5.3.4.6.  Normalization . . . . . . . . . . . . . . . . . .  30
       5.3.5.  FLOAT . . . . . . . . . . . . . . . . . . . . . . . .  31
         5.3.5.1.  Value Type Notation . . . . . . . . . . . . . . .  31
         5.3.5.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  31
         5.3.5.3.  Format Definition . . . . . . . . . . . . . . . .  31
         5.3.5.4.  Description . . . . . . . . . . . . . . . . . . .  31
         5.3.5.5.  Examples  . . . . . . . . . . . . . . . . . . . .  31
         5.3.5.6.  Normalization . . . . . . . . . . . . . . . . . .  31
       5.3.6.  LANGUAGE-TAG  . . . . . . . . . . . . . . . . . . . .  32
         5.3.6.1.  Value Type Notation . . . . . . . . . . . . . . .  32
         5.3.6.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  32
         5.3.6.3.  Format Definition . . . . . . . . . . . . . . . .  32
         5.3.6.4.  Description . . . . . . . . . . . . . . . . . . .  32
         5.3.6.5.  Examples  . . . . . . . . . . . . . . . . . . . .  32
         5.3.6.6.  Normalization . . . . . . . . . . . . . . . . . .  32
       5.3.7.  Binary  . . . . . . . . . . . . . . . . . . . . . . .  33
         5.3.7.1.  Value Type Notation . . . . . . . . . . . . . . .  33
         5.3.7.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  33
         5.3.7.3.  Format Definition . . . . . . . . . . . . . . . .  33
         5.3.7.4.  Description . . . . . . . . . . . . . . . . . . .  33
         5.3.7.5.  Example . . . . . . . . . . . . . . . . . . . . .  33
       5.3.8.  KEYVALUE  . . . . . . . . . . . . . . . . . . . . . .  34
         5.3.8.1.  Value Type Notation . . . . . . . . . . . . . . .  34
         5.3.8.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  34



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         5.3.8.3.  Format Definition . . . . . . . . . . . . . . . .  34
         5.3.8.4.  Description . . . . . . . . . . . . . . . . . . .  34
         5.3.8.5.  Examples  . . . . . . . . . . . . . . . . . . . .  34
         5.3.8.6.  Normalization . . . . . . . . . . . . . . . . . .  34
     5.4.  Date and Time Value Types . . . . . . . . . . . . . . . .  34
       5.4.1.  ISO-DATE-COMPLETE . . . . . . . . . . . . . . . . . .  35
         5.4.1.1.  Value Type Notation . . . . . . . . . . . . . . .  35
         5.4.1.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  35
         5.4.1.3.  Format Definition . . . . . . . . . . . . . . . .  35
         5.4.1.4.  Description . . . . . . . . . . . . . . . . . . .  35
         5.4.1.5.  Example . . . . . . . . . . . . . . . . . . . . .  35
         5.4.1.6.  Normalization . . . . . . . . . . . . . . . . . .  35
       5.4.2.  ISO-DATE-FLEX . . . . . . . . . . . . . . . . . . . .  35
         5.4.2.1.  Value Type Notation . . . . . . . . . . . . . . .  36
         5.4.2.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  36
         5.4.2.3.  Format Definition . . . . . . . . . . . . . . . .  36
         5.4.2.4.  Description . . . . . . . . . . . . . . . . . . .  36
         5.4.2.5.  Normalization . . . . . . . . . . . . . . . . . .  37
       5.4.3.  ISO-TIME-COMPLETE . . . . . . . . . . . . . . . . . .  37
         5.4.3.1.  Value Type Notation . . . . . . . . . . . . . . .  37
         5.4.3.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  37
         5.4.3.3.  Format Definition . . . . . . . . . . . . . . . .  38
         5.4.3.4.  Description . . . . . . . . . . . . . . . . . . .  38
         5.4.3.5.  Normalization . . . . . . . . . . . . . . . . . .  39
       5.4.4.  ISO-TIME-BASIC  . . . . . . . . . . . . . . . . . . .  39
         5.4.4.1.  Value Type Notation . . . . . . . . . . . . . . .  39
         5.4.4.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  39
         5.4.4.3.  Format Definition . . . . . . . . . . . . . . . .  39
         5.4.4.4.  Description . . . . . . . . . . . . . . . . . . .  39
         5.4.4.5.  Normalization . . . . . . . . . . . . . . . . . .  40
       5.4.5.  ISO-TIME-FLEX . . . . . . . . . . . . . . . . . . . .  40
         5.4.5.1.  Value Type Notation . . . . . . . . . . . . . . .  40
         5.4.5.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  40
         5.4.5.3.  Format Definition . . . . . . . . . . . . . . . .  40
         5.4.5.4.  Description . . . . . . . . . . . . . . . . . . .  41
         5.4.5.5.  Normalization . . . . . . . . . . . . . . . . . .  42
       5.4.6.  ISO-UTC-OFFSET  . . . . . . . . . . . . . . . . . . .  42
         5.4.6.1.  Value Type Notation . . . . . . . . . . . . . . .  42
         5.4.6.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  42
         5.4.6.3.  Format Definition . . . . . . . . . . . . . . . .  42
         5.4.6.4.  Example . . . . . . . . . . . . . . . . . . . . .  43
         5.4.6.5.  Normalization . . . . . . . . . . . . . . . . . .  43
       5.4.7.  CAL-UTC-OFFSET  . . . . . . . . . . . . . . . . . . .  43
         5.4.7.1.  Value Type Notation . . . . . . . . . . . . . . .  43
         5.4.7.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  43
         5.4.7.3.  Format Definition . . . . . . . . . . . . . . . .  43
         5.4.7.4.  Description:  . . . . . . . . . . . . . . . . . .  43
         5.4.7.5.  Example . . . . . . . . . . . . . . . . . . . . .  44



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         5.4.7.6.  Normalization . . . . . . . . . . . . . . . . . .  44
       5.4.8.  ISO-DATE-TIME-COMPLETE  . . . . . . . . . . . . . . .  44
         5.4.8.1.  Value Type Notation . . . . . . . . . . . . . . .  44
         5.4.8.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  44
         5.4.8.3.  Format Definition . . . . . . . . . . . . . . . .  44
         5.4.8.4.  Description . . . . . . . . . . . . . . . . . . .  45
         5.4.8.5.  Examples  . . . . . . . . . . . . . . . . . . . .  45
         5.4.8.6.  Normalization . . . . . . . . . . . . . . . . . .  45
       5.4.9.  ISO-DATE-TIME-BASIC . . . . . . . . . . . . . . . . .  45
         5.4.9.1.  Value Type Notation . . . . . . . . . . . . . . .  45
         5.4.9.2.  Purpose . . . . . . . . . . . . . . . . . . . . .  45
         5.4.9.3.  Format Definition . . . . . . . . . . . . . . . .  46
         5.4.9.4.  Description . . . . . . . . . . . . . . . . . . .  46
         5.4.9.5.  Examples  . . . . . . . . . . . . . . . . . . . .  46
         5.4.9.6.  Normalization . . . . . . . . . . . . . . . . . .  46
       5.4.10. ISO-DATE-TIME-FLEX  . . . . . . . . . . . . . . . . .  46
         5.4.10.1.  Value Type Notation  . . . . . . . . . . . . . .  46
         5.4.10.2.  Purpose  . . . . . . . . . . . . . . . . . . . .  46
         5.4.10.3.  Format Definition  . . . . . . . . . . . . . . .  47
         5.4.10.4.  Description  . . . . . . . . . . . . . . . . . .  47
         5.4.10.5.  Examples . . . . . . . . . . . . . . . . . . . .  47
         5.4.10.6.  Normalization  . . . . . . . . . . . . . . . . .  47
       5.4.11. ISO-DATE-AND-OR-TIME  . . . . . . . . . . . . . . . .  47
         5.4.11.1.  Value Type Notation  . . . . . . . . . . . . . .  47
         5.4.11.2.  Purpose  . . . . . . . . . . . . . . . . . . . .  47
         5.4.11.3.  Format Definition  . . . . . . . . . . . . . . .  48
         5.4.11.4.  Description  . . . . . . . . . . . . . . . . . .  48
         5.4.11.5.  Example  . . . . . . . . . . . . . . . . . . . .  48
         5.4.11.6.  Normalization  . . . . . . . . . . . . . . . . .  49
       5.4.12. ISO-DURATION-COMPLETE . . . . . . . . . . . . . . . .  49
         5.4.12.1.  Value Type Notation  . . . . . . . . . . . . . .  49
         5.4.12.2.  Purpose  . . . . . . . . . . . . . . . . . . . .  49
         5.4.12.3.  Format Definition  . . . . . . . . . . . . . . .  49
         5.4.12.4.  Description  . . . . . . . . . . . . . . . . . .  49
         5.4.12.5.  Examples . . . . . . . . . . . . . . . . . . . .  50
         5.4.12.6.  Normalization  . . . . . . . . . . . . . . . . .  50
       5.4.13. CAL-DURATION  . . . . . . . . . . . . . . . . . . . .  51
         5.4.13.1.  Value Type Notation  . . . . . . . . . . . . . .  51
         5.4.13.2.  Purpose  . . . . . . . . . . . . . . . . . . . .  51
         5.4.13.3.  Format Definition  . . . . . . . . . . . . . . .  51
         5.4.13.4.  Description  . . . . . . . . . . . . . . . . . .  51
         5.4.13.5.  Example  . . . . . . . . . . . . . . . . . . . .  52
         5.4.13.6.  Normalization  . . . . . . . . . . . . . . . . .  53
       5.4.14. ISO-INTERVAL  . . . . . . . . . . . . . . . . . . . .  53
         5.4.14.1.  Value Type Notation  . . . . . . . . . . . . . .  53
         5.4.14.2.  Purpose  . . . . . . . . . . . . . . . . . . . .  53
         5.4.14.3.  Format Definition  . . . . . . . . . . . . . . .  53
         5.4.14.4.  Description  . . . . . . . . . . . . . . . . . .  53



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         5.4.14.5.  Examples . . . . . . . . . . . . . . . . . . . .  55
         5.4.14.6.  Normalization  . . . . . . . . . . . . . . . . .  55
       5.4.15. CAL-INTERVAL  . . . . . . . . . . . . . . . . . . . .  55
         5.4.15.1.  Value Type Notation  . . . . . . . . . . . . . .  55
         5.4.15.2.  Purpose  . . . . . . . . . . . . . . . . . . . .  55
         5.4.15.3.  Format Definition  . . . . . . . . . . . . . . .  55
         5.4.15.4.  Description  . . . . . . . . . . . . . . . . . .  55
         5.4.15.5.  Examples . . . . . . . . . . . . . . . . . . . .  56
         5.4.15.6.  Normalization  . . . . . . . . . . . . . . . . .  57
   6.  Normalization . . . . . . . . . . . . . . . . . . . . . . . .  57
     6.1.  Approach  . . . . . . . . . . . . . . . . . . . . . . . .  57
     6.2.  Steps . . . . . . . . . . . . . . . . . . . . . . . . . .  58
     6.3.  Application on alternative serializations . . . . . . . .  59
   7.  Client Implementations Recommendations  . . . . . . . . . . .  59
   8.  CardDAV . . . . . . . . . . . . . . . . . . . . . . . . . . .  59
     8.1.  Additional Server Semantics for PUT, COPY and MOVE  . . .  59
       8.1.1.  Provide Normalized Output . . . . . . . . . . . . . .  59
   9.  CalDAV  . . . . . . . . . . . . . . . . . . . . . . . . . . .  60
     9.1.  Additional Server Semantics for PUT, COPY and MOVE  . . .  60
       9.1.1.  Provide Normalized Output . . . . . . . . . . . . . .  60
   10. Security Considerations . . . . . . . . . . . . . . . . . . .  60
   11. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  60
     11.1.  Common vObject Registries  . . . . . . . . . . . . . . .  61
     11.2.  vObject Component Uniqueness Identifiers Registry  . . .  61
       11.2.1.  Registration Procedure . . . . . . . . . . . . . . .  61
       11.2.2.  Registration Template  . . . . . . . . . . . . . . .  61
       11.2.3.  Initial Registrations  . . . . . . . . . . . . . . .  62
   12. Mapping Of Data Value Types For Existing RFCs . . . . . . . .  63
     12.1.  RFC 6350 . . . . . . . . . . . . . . . . . . . . . . . .  63
     12.2.  RFC 5545 . . . . . . . . . . . . . . . . . . . . . . . .  64
       12.2.1.  RECURMAP . . . . . . . . . . . . . . . . . . . . . .  64
   13. Mapping Of Component Property Value Types For Existing RFCs .  65
     13.1.  VCARD Component (RFC 6350) . . . . . . . . . . . . . . .  65
     13.2.  VCALENDAR Component (RFC 5545) . . . . . . . . . . . . .  67
     13.3.  VEVENT Component (RFC 5545)  . . . . . . . . . . . . . .  67
     13.4.  VTODO Component (RFC 5545) . . . . . . . . . . . . . . .  69
     13.5.  VJOURNAL Component (RFC 5545)  . . . . . . . . . . . . .  70
     13.6.  VFREEBUSY Component (RFC 5545) . . . . . . . . . . . . .  71
     13.7.  VTIMEZONE Component (RFC 5545) . . . . . . . . . . . . .  71
     13.8.  STANDARD / DAYLIGHT Components (RFC 5545)  . . . . . . .  71
     13.9.  VALARM Component (RFC 5545)  . . . . . . . . . . . . . .  72
   14. Mapping Of Parameter Value Types For Existing RFCs  . . . . .  72
     14.1.  RFC 6350 . . . . . . . . . . . . . . . . . . . . . . . .  72
     14.2.  RFC 5545 . . . . . . . . . . . . . . . . . . . . . . . .  73
   15. References  . . . . . . . . . . . . . . . . . . . . . . . . .  73
     15.1.  Normative References . . . . . . . . . . . . . . . . . .  74
     15.2.  Informative References . . . . . . . . . . . . . . . . .  74
   Appendix A.  Normalization Examples for vFormat . . . . . . . . .  77



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     A.1.  vCard . . . . . . . . . . . . . . . . . . . . . . . . . .  77
   Appendix B.  Acknowledgements . . . . . . . . . . . . . . . . . .  78
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  78

1.  Introduction

   The ubiquitous vCard [RFC6350] and iCalendar [RFC5545] standards are
   known as the "vObject" or "VCOMPONENT" family of standards.  Named by
   the convention where the component type identifiers usually start
   with the letter "v", all of them use very similar, if not identical,
   syntax.

   While the origin of these formats have a shared history, due to
   diverged implementations of "vObject" standards, the serialization of
   such formats often generate different output even when given
   identical content, causing interoperability concerns and the general
   inability to determine equivalence of vObjects for integrity concerns
   (2.1.2 [RFC3552]).

   This document:

   o  defines the "vObject" data model, a generalization of the implied
      data models of vObject-compliant standards;

   o  defines the "vFormat" serialization syntax, a generalized syntax
      of vObject-compliant serialization formats;

   o  provides the "vObject Value Type" notation syntax, a method to
      define value schema of all properties in vObject-compliant
      standards; and

   o  describes the normalized form of the vObject data model and the
      normalization process for vFormat syntax.

   The normalized forms and normalization methods described in this
   document are fully compatible with the vObject-compliant standards,
   including vCard 4.0 [RFC6350] and iCalendar [RFC5545].

   This is a work product of the CalConnect TC-VCARD [CALCONNECT-VCARD]
   and TC-CALENDAR [CALCONNECT-CALENDAR] committees.

2.  Terms and Definitions

   The key words "*MUST*", "*MUST NOT*", "*REQUIRED*", "*SHALL*",
   "*SHALL NOT*", "*SHOULD*", "*SHOULD NOT*", "*RECOMMENDED*", "*NOT
   RECOMMENDED*", "*MAY*", and "*OPTIONAL*" in this document are to be
   interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only
   when, they appear in all capitals, as shown here.



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   The key words "*Private Use*", "*Experimental Use*", "*Hierarchical
   Allocation*", "*First Come First Served*", "*Expert Review*",
   "*Specification Required*", "*RFC Required*", "*IETF Review*",
   "*Standards Action*" and "*IESG Approval*" in this document are to be
   interpreted as described in 4 [RFC8126].

   Notation in this document is described in ABNF [RFC5234] as used by
   [RFC6350].

   Definitions from [RFC6350] apply to this specification except when
   explicitly overridden.

   All names of properties, property parameters, enumerated property
   values, and property parameter values are case-insensitive.  However,
   all property values are case-sensitive, unless otherwise stated.

2.1.  Definitions

   vObject
      the generalized data model of the vCard component (VCARD) and
      iCalendar (VCALENDAR) component defined in this document

   vFormat
      the native serialization format of vObject, which is the textual
      format representation using the "BEGIN:" and "END:" component
      keywords

   inner vObject, sub-component
      a vObject located within a vObject

   outer vObject, super-component
      a vObject that this vObject is located within

   Client User Application (CUA)
      the vObject client implementation that interfaces with the user

   calendar date
      as defined in 2.1.8 [ISO.8601.2004]

3.  vObject Data Model

   The vObject data model is the generalized data model from the implied
   data models of vCard [RFC6350] and iCalendar [RFC5545].

   While both vCard [RFC6350] and iCalendar [RFC5545] specify data
   formats for different purposes, the data model behind them follow an
   identical logical structure (using components, properties and
   parameters) with similar requirements.



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   By creating a generalized data model ("vObject") that is compatible
   with both, we are able to ensure that newly developed data
   modification techniques for vObject would be interoperable on all
   other vObject-compliant models.

3.1.  vObject-compliant Models

   The implied data models behind these formats are compliant to the
   vObject data model:

   o  vCard version 4.0 [RFC6350]: the VCARD component

   o  Internet Calendaring and Scheduling Core Object Specification
      (iCalendar) [RFC5545], the VCALENDAR, VEVENT, VJOURNAL, VFREEBUSY,
      VTIMEZONE, VALARM, VTODO, STANDARD, DAYLIGHT components

   o  Calendar Availability Extensions [RFC7953]: the VAVAILABILITY,
      AVAILABLE components

   o  iCalendar Patching [VPATCH]: the VPATCH component

3.2.  Elements

   Data within a vObject is arranged through a logical hierarchy
   composed of the following elements:

   o  component;

   o  property;

   o  property parameter;

   o  property value;

   o  property parameter value; and

   o  property group.

   The property group is optional and *MAY* not be accepted by all
   vObject-compliant models.











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           +-------------------+
           | vObject Component |
           +-------------------+
               |
           / - - - - - - - - - - - - - - \
           |   |              (Optional) |
               |   +----------------+
           |   +---| Property Group |    |
               |   +----------------+
           |   |                         |
           \ - - - - - - - - - - - - - - /
               |   +----------+
               +---| Property |
                   +----------+
                       |
                       |   +----------------+
                       +---| Property Value |
                       |   +----------------+
                       |
                       |   +--------------------+
                       +---| Property Parameter |
                           +--------------------+
                               |
                               |   +--------------------------+
                               +---| Property Parameter Value |
                                   +--------------------------+

                  Figure 1: vObject Data Model Hierarchy

3.2.1.  Equivalence

   Two vObjects are considered identical in content if their normalized
   forms are textually equivalent.

3.3.  Component

   A vObject is based on the representation of the "component" element.
   All vObjects are composed of at least one component element.

   A component:

   o  *MAY* contain vObject components;

   o  *MAY* contain properties; and

   o  *MUST* contain a uniqueness identifier property whose value is
      called the component's "unique identifier".




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   A component type is identified by the component name, and every
   component instance is distinguished by the value of its uniqueness
   identifier property.

   A component is often used to model an object in the object-oriented
   sense, such as a vCard or an iCalendar object.

   The order of components *MAY* represent order of the objects, which
   is important for example in a "VPATCH" component [VPATCH],
   representing the patching order, which is not a commutative process.

3.3.1.  Uniqueness Identifying Property

   As a vObject component can contain inner components, it is important
   that those inner components can be distinguished from each other.

   A vObject component's uniqueness identifier property is a property
   whose value can uniquely identify the immediate component that
   contains it.

   Every vObject component *MUST* contain a single, component uniqueness
   identifier property.  The uniqueness identifier property can be
   different according to component types, and the uniqueness scope of
   that property *MAY* be different.  At a minimum, the uniqueness
   identifier property value *MUST* be unique within the immediate
   component that contains the uniqueness identifier property.

   For example:

   o  a "VCARD" component can be distinguished among other "VCARD"
      components by its "UID" property value that is globally unique;

   o  a "STANDARD" component of "VTIMEZONE" can be distinguished
      according to its "DTSTART" property within the "VTIMEZONE"
      component that contains it.

   The list of uniqueness identifier properties for every vObject
   component that complies with this document can be found in the IANA
   registry described in Section 11.2.

   New vObject components defined according to this document *MUST*
   define a uniqueness identifier property for that component, and it
   *MUST* be registered in the said IANA registry.








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3.3.2.  Normalizing A Component

3.3.2.1.  Sorted Component Properties

   Properties *MUST* be first normalized and before sorted, meaning that
   the property's values, and its parameters and its values, have been
   normalized.

   The sorting of component properties *MUST* be performed according to
   the following order:

   o  alphabetically by the property name.  If a property spans multiple
      content lines, the content lines *MUST NOT* be separated after
      sorting.

   o  alphabetically by their normalized value.

   o  alphabetically by treating its parameters as long strings

3.3.2.2.  Sorted Inner Components

   Inner components within a vObject must be placed in a sorted order.

   The sorting between components *MUST* be performed according to the
   following order:

   o  alphabetically by component type, according to component name,
      such as "VCALENDAR"; then

   o  if of the same component name, alphabetically according to its
      unique identifier Section 3.3.1.

3.3.2.3.  Normalized Inner Components

   An inner component *MUST* itself be normalized, meaning that its
   properties and inner components *MUST* be normalized.

3.3.3.  vObject Property

   Properties represent attributes of the vObject itself.

   A property:

   o  *MUST* contain a value;

   o  *MAY* contain one or more property parameters.

   vObject property value types are listed in Section 3.3.4.



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3.3.3.1.  Normalized Values

   A normalized property *MUST* have normalized values.

3.3.3.2.  Normalized Parameters

   A normalized property *MUST* have normalized property parameters.

   Property parameters within the same property *MUST* each be
   normalized, and then sorted by parameter name alphabetically.

   Property parameters of the same property *MUST* have unique names.

3.3.4.  Property Value

   A vObject property *MAY* have one or more values, depending on the
   value type.

   vObject property values are strongly typed, just like in [RFC5545]
   and [RFC6350].  Basic value types accepted in vObject properties are
   defined in Section 5.

   vObject compliant formats *MAY* define additional value types that
   are not provided in this document, and *MAY* require separate
   validation rules, such as the "RECUR" property value type from
   iCalendar [RFC5545].

   Each property *MUST* define a default value type, and *MAY* accept
   alternative, defined, value types.

3.3.5.  Normalization Of Property Values

   The property value generally does not require any normalization.
   Please consult individual normalization instructions in each value
   type's definition.

3.3.6.  Property Parameter

   A property parameter is an attribute that applies on a property.

   A property parameter contains:

   o  an identifier identifying its type;

   o  the value of the property parameter.

   A property parameter *MAY* represent:




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   o  information about the property; or

   o  information about the property value

   A property *MAY* have multiple property parameters, for example, the
   "TYPE" of the value or a category that applies to this value.

3.3.6.1.  Value Lists

   Certain property parameters allow multiple values.  There is no
   defined order among property parameters in a property parameter list.

   In normalized form, values in a value list *MUST* be sorted
   alphabetically.

3.3.7.  Default Property Parameter Values

   Property parameters are allowed to have a default value.

   For example, in vObject formats including [RFC5545] and [RFC6350],
   each property value has a specified data type specified as the
   "VALUE" property parameter.

3.3.8.  Property Parameter Value

   vObject property parameter values are strongly typed, just like
   vObject properties, [RFC5545] and [RFC6350].  Basic value types
   accepted in vObject property parameter values are defined in
   Section 5.

   A property parameter value **MAY* contain none, one or several
   property parameter values.  No order is defined among a list of
   property parameter values.

   vObject compliant formats *MAY* define additional value types that
   are not provided in this document, and *MAY* require separate
   validation rules, such as the values accepted by the "FBTYPE"
   property parameter in iCalendar [RFC5545].

   Each property parameter *MUST* define its accepted value type.  While
   a property *MAY* accept multiple alternative value types, a property
   parameter value *MUST* only accept one value type.

3.3.9.  Normalizing Multiple Parameter Values

   Property parameter values within a property parameter is considered
   sorted by value.




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3.3.10.  Property Group

   A property group (or just "group") is used to group a set of
   properties, useful to represent cases where a group of properties are
   closely related to each other.

   In the vCard [RFC6350], the group is used to tie multiple properties
   into being displayed together.

   Each property *MUST* only have a maximum of one group.

   Groups are not ordered and group names are case-insensitive.

4.  vFormat Syntax

   The "vFormat" format is the generalized syntax from the vCard
   [RFC6350] and iCalendar [RFC5545] formats, and is the native format
   for vObject serialization ("vObject native format").

   vFormat is called the "native" format for vObjects to distinguish it
   from alternative representations of vObject data, such as their XML
   (xCal, xCard) or JSON (jCal, jCard) representations.

   Its syntax originated from the textual representation of the
   iCalendar and vCard formats, and is mostly traceable back to the
   original vCard and iCalendar specifications [vCard21].

   Both of these formats are considered "instances" (or "downstream
   formats") of vFormat, and fully adhere to vFormat requirements.

   Parsing and modification operations that work on vFormat *SHOULD*
   work on all its instances, including iCalendar [RFC5545] and vCard
   [RFC6350].

4.1.  ABNF Format Definition

   The following ABNF notation defines the vFormat syntax, in accordance
   with [RFC5234], which also defines CRLF, WSP, DQUOTE, VCHAR, ALPHA,
   and DIGIT.

   A vObject is defined by the following notation in vFormat:

   vobjects = 1*vobject

   vobject = "BEGIN:" comp-name CRLF
             *contentline
             *vobject
             "END:" comp-name CRLF



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   comp-name = name

   prop-name = name

   prop-values = prop-value / prop-list / prop-structured

   prop-value = VALUE-CHAR

   prop-list = prop-value *("," prop-value)
     ; An unordered list containing multiple property values

   prop-structured = prop-value *(";" prop-value)
     ; A structured list that consist of multiple property fields
     ; for multiple property values

   contentline = [group "."] prop-name params ":" prop-values CRLF
     ; Folding and unfolding procedures described in Section 3.2 of
     ; [RFC6350] applies:
     ;   * When parsing a content line, folded lines *MUST* first be
     ;     unfolded accordingly.
     ;   * When generating a content line, lines longer than 75
     ;     characters *SHOULD* be folded accordingly.
     ;   * When normalizing a content line, the content line *MUST*
     ;     be folded when the line is longer than 75 characters.

   group = name

   params = *(";" param)

   param = name "=" param-value *("," param-value)
     ; Allowed parameters depend on property name.

   name = 1*(ALPHA / DIGIT / "-")

   NON-ASCII = UTF8-2 / UTF8-3 / UTF8-4
     ; UTF8-{2,3,4} are defined in <<RFC3629>>
     ; TODO: generalize this to UTF-32

   QSAFE-CHAR = WSP / "!" / %x23-7E / NON-ASCII
     ; Any character except CTLs, DQUOTE

   SAFE-CHAR = WSP / "!" / %x23-39 / %x3C-7E / NON-ASCII
     ; Any character except CTLs, DQUOTE, ";", ":"

   VALUE-CHAR = WSP / VCHAR / NON-ASCII
     ; Any textual character





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4.2.  Component

   A component:

   o  begins with line of text that starts with "BEGIN:" following with
      its component name, ending with a line break;

   o  ends with a line of text that starts with "END:" following with
      its component name (matching with the "BEGIN:" line), ending with
      a line break.

   The vCard [RFC6350] and iCalendar [RFC5545] data formats both conform
   to vFormat, and their syntaxes are considered to be restricted
   instances of the vObject syntax.

4.2.1.  Component Name In Uppercase

   The component name of a vObject *MUST* be uppercased, for both the
   "BEGIN:" and "END:" content lines.

   Example:

   "BEGIN:vCard"

   Should be normalized to:

   "BEGIN:VCARD"

4.2.2.  Order Of Inner Components And Properties

   Properties *MUST* be placed before inner components are listed.

4.2.3.  Maintain Validity

   Certain vObject formats places certain restrictions or requirements
   on property line locations.  Normalization procedures *MUST NOT*
   affect the validity of the normalized vObject.

   For example, in the VCARD component [RFC6350], the "VERSION" property
   line is *REQUIRED* to be placed immediately below the "BEGIN" line.

   In this case, when normalizing the VCARD component, the common
   normalization procedure *MUST* be first applied, and the "VERSION"
   property line *MUST* be restored to the valid location as required by
   its specifications [RFC6350].






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4.3.  Property

   A property can be represented by one content line (a line that ends
   with a line break), but can also be "folded" (3.1 [RFC5545]) to use
   multiple lines.

   A property begins with the property name (e.g., "TEL"), followed by a
   COLON delimiter and the property's value.

4.3.1.  Uppercased Property Name

   The property name *MUST* be normalized to uppercase letters.

4.3.2.  Normalized Parameters

   The last property parameter of a property *MUST NOT* have a trailing
   SEMICOLON.

4.3.3.  Wrapped Content Line

   When exporting a normalized property content line, it *MUST* be
   folded at the character limit when it exceeds 75 characters.  Each
   folded line *MUST* be delimited by the character sequence of a line
   break and a single white space (CRLF, SPACE (U+0020)).  This rule
   only applies to normalized output.

   For example, the original form:

NOTE:This is a very long description on a long line that exceeds 75 characters.

   When exported to normalized output *MUST* give out:

NOTE:This is a very long description on a long line that exceeds 75 charac
 ters.

4.4.  Property Value

   The property's values are defined as the content after the property
   name and COLON delimiter, until the end of the unfolded content line.

   If a property accepts multiple values, the definition of delimitation
   is defined in Section 5.

   vObject compliant formats that defines additional value types *MAY*
   require separate validation rules on top of vFormat syntax.






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   If the property value type of a property value is not the default
   value type, the "VALUE" parameter *MUST* be present to specify the
   type of the property value.

   vFormat representation of different value types are provided in
   Section 5.

4.4.1.  Normalizing Property Values

   The property value generally does not require any normalization.

4.5.  Property Parameter

   Property parameters exist between the property name and the COLON
   delimiter in a property line.

   Each property parameter in a list of property parameters *MUST* be
   separated by a SEMICOLON character.

   The property parameter name and the property parameter value is
   separated with an equal sign ("=").

4.5.1.  Multiple Property Parameters

   If the property accepts multiple property parameters values, they
   *MUST* be separated by a SEMICOLON character as a list.

4.5.2.  Expanded Form Of Property Parameter Value List

   When there are multiple instances of a property parameter on the same
   property, such as in "TYPE=home;TYPE=work", it is considered
   equivalent to "TYPE=home\,work".

4.5.3.  Uppercased Property Parameter Names

   The property parameter name *MUST* be normalized into uppercase
   letters in form of a Unicode string (7 [RFC8259]).

   Property parameter names (together with their values) *MUST* be
   sorted alphabetically.

   Example:

   "TEL;VALUE=uri;type=home:tel:+1-888-888-8888"

   The normalized form is:

   "TEL;TYPE="home";VALUE="uri":tel:+1-888-888-8888"



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4.5.4.  Join Identical Property Parameter Names

   If a property parameter occurs more than once within a property, the
   property parameter is considered to contain a list of property
   parameter values joined by the parameter separator.

   Such instances of property parameters with identical names *MUST* be
   joined into one instance with its value a sorted list of the property
   parameter values.

   For example, the vCard "TEL" property's "TYPE" parameter [RFC6350]
   describes that "TYPE=home,work" and "TYPE=work;TYPE=home" are
   considered equivalent.

   Example:

   "TEL;TYPE=home;Type=work;VALUE=uri:tel:+1-888-888-8888"

   The normalized form is:

   "TEL;TYPE="home","work";VALUE=uri:tel:+1-888-888-8888"

4.5.5.  Express Default Property Value Types

   In vObject formats including [RFC5545] and [RFC6350], each property
   value has a specified data type either as specified by property
   definition or optionally assigned.

   When normalizing a property, the property data value type *MUST*
   always be specified.  If the value type is not explicitly specified,
   it *MUST* be filled in according to the vObject format.

   Example:

   "TEL:+1-888-888-8888"

   The normalized form is:

   "TEL;VALUE="text":+1-888-888-8888"

4.6.  Property Parameter Value

   While a property parameter value may accept any vObject value type,
   the serialization rules of a vFormat property value and a vFormat
   property parameter value are different, due to further limitations of
   allowed characters in property parameter values.





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4.6.1.  Format Definition

   param-value          = param-single-value *("," param-single-value)
   param-single-value   = paramtext / quoted-string

   paramtext     = *SAFE-CHAR
   quoted-string = DQUOTE *QSAFE-CHAR DQUOTE

   QSAFE-CHAR    = WSP / %x21 / %x23-7E / NON-US-ASCII
       ; Any character except CONTROL and DQUOTE

   SAFE-CHAR     = WSP / %x21 / %x23-2B / %x2D-39 / %x3C-7E
                / NON-US-ASCII
       ; Any character except CONTROL, DQUOTE, ";", ":", ","

   NON-US-ASCII  = UTF8-2 / UTF8-3 / UTF8-4
        ; UTF8-2, UTF8-3, and UTF8-4 are defined in [RFC3629]

   CONTROL       = %x00-08 / %x0A-1F / %x7F
        ; All the controls except HTAB

4.6.2.  Description

   In vFormat, if a property parameter accepts multiple values, these
   value elements *MUST* be separated by a COMMA (U+002C).

   The DQUOTE character is used as a delimiter for parameter values that
   contain restricted characters or URI text.

   Property parameter values that contain the COLON (U+003A), SEMICOLON
   (U+003B) (such as the "LIST" and "MAP" value types), or COMMA
   (U+002C) character separators *MUST* be specified as quoted-string
   text values.

   Property parameter values that contain the DQUOTE (U+0022) character
   *MUST* be escaped and specified as quoted-string text values.

   An intentional line break *MUST* be represented by the sequence of
   "\n" or "\N" (BACKSLASH followed by a LATIN SMALL LETTER N (U+006E)
   or a LATIN CAPITAL LETTER N (U+004E)).

   Property parameter values that are not in quoted-strings are case-
   insensitive.








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4.6.3.  Example

   The value "cid:part1.0001@example.org" in the parameter "ALTREP"
   within a "DESCRIPTION" property in iCalendar can be specified like
   this:

   DESCRIPTION;ALTREP="cid:part1.0001@example.org":The Fall'98 Wild
    Wizards Conference - - Las Vegas\, NV\, USA

4.6.4.  Normalization of Line Breaks

   In vFormat, vObject property parameter values *MUST* convert all line
   breaks ("\n" or "\N") into the character sequence "\n" (BACKSLASH
   followed by a LATIN SMALL LETTER N (U+006E)).

   If a value is specified as "paramtext" (i.e., not inside a quoted-
   string), the value *SHOULD* be down-cased.

4.6.5.  Normalizing Parameter Values Via DQOUTE Wrapping

   vFormat property parameter values *SHOULD* be individually wrapped
   with the DQUOTE characters.

   This is an example application of the rule from [RFC6350]:

   "TEL;TYPE=home,work;VALUE=uri:tel:+1-888-888-8888"

   The normalized vFormat output is:

   "TEL;TYPE="home","work";VALUE="uri":tel:+1-888-888-8888"

4.7.  Property Group

   The syntax of a property group is defined in Section 4.1.

   Property groups *MUST NOT* be removed during normalization.  This is
   contrary to [RFC6350] that allows stripping off groups.

5.  vObject Value Types And Notation Syntax

   vObject value types are identically defined for both:

   o  vObject property values; and

   o  vObject property parameter values.






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5.1.  Value Type Notation

   The vObject value type notation is used for defining the accepted
   values within a vObject property or parameter values.  It fully
   covers all complete and exhaustive amongst all vObject-compliant
   standards.

   This notation syntax allows a vObject specification to define complex
   value types by using one or more value primitives defined in the
   sections below.

   The purpose of this syntax is to provide a mechanism to all vObject
   value definitions, such that any new vObject mechanism (such as, a
   method that can be applied to any vObject) can ensure uniform
   applicability on vObject values.

   Value type mappings provided in Section 12, Section 14, and
   Section 13 are denoted using the vObject value type syntax.

   Implementation differences within Section 4 of the same value type
   are described in Section 4.4 and Section 4.6.

5.2.  Meta Value Types

   Meta value types are used in conjunction with basic value types
   (Section 5.3).

5.2.1.  FIELDSET

   Some properties and parameters require values defined in terms of
   multiple parts.

   This construct of multiple structured values is called a "FIELDSET".
   Each value in FIELDSET *MUST* have the same value type as defined.

5.2.1.1.  Value Type Notation

   When used to describe a value type, the "FIELDSET(field-1-value-type,
   ...)" notation is defined as a structure of fields separated by the
   SEMICOLON character, where each of its fields is of value type
   "field-i-value-type", where "i" represents the index of the specific
   field.

5.2.1.2.  Example 1

   The "CLIENTPIDMAP" property of [RFC6350] takes a tuple of "INTEGER"
   and "URI".




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   The notation in vObject given for its value type would be this
   indicating that the first value is an INTEGER, while the latter value
   is a URI:

   FIELDSET(INTEGER, URI)

5.2.1.3.  Example 2

   The "N" property of [RFC6350] defines its value of having 5 values at
   once, and each of these values are a LIST of TEXT.

   The notation in vObject given for its value type would be this
   indicating that there are 5 fields in this FIELDSET, and each value
   element of it *MUST* be a LIST of TEXT elements:

   FIELDSET(5\*LIST(TEXT))

5.2.1.4.  Normalizing a FIELDSET

   When normalizing a FIELDSET, each value *MUST* have been normalized,
   but the order of FIELDSET elements *MUST NOT* be rearranged.

5.2.2.  LIST

   Properties and parameters *MAY* specify its value to be an unordered
   list of values.  There is no significance to the order of values in a
   list.

   This construct is called the "LIST".  Each value in the LIST *MUST*
   have the same value type.

5.2.2.1.  Value Type Notation

   The "LIST(value-type)" notation is used to describe this value type,
   of a list of elements, where each of its elements is of value type
   "value-type".

5.2.2.2.  Example 1

   The "NICKNAME" property of [RFC6350] defines its value to be an
   unordered list of TEXT.

   In vObject notation its value type is defined to be:

   LIST(TEXT)






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5.2.2.3.  Example 2

   The "RECUR" property of [RFC5545] defines its value to be an
   unordered list of ASSIGN.

   In vObject notation its value type is defined to be:

   LIST(KEYVALUE, ";")

5.2.2.4.  Normalizing a LIST

   When normalizing a LIST, each value of it *MUST* be normalized, and
   the values *MUST* be sorted alphabetically.

   For example, values of [RFC5545] RESOURCES, FREEBUSY, EXDATE, RDATE,
   CATEGORIES, *MUST* be sorted alphabetically when normalized.

5.2.3.  MAP

   A "MAP" serves the function of a key-value table.  It is realized
   using the "LIST" value type with values of the value type "KEYVALUE".

   Each value in the MAP *MUST* use the "KEYVALUE" value type.

   There is no inherent order of the values within a MAP.  Values within
   its key value pairs *MAY* be of different value types as defined.

5.2.3.1.  Value Type Notation

   This value type is described using the "MAP(kv_1, kv_2, ...)"
   notation, where each "kv_i" represents a property of the value type
   KEYVALUE.

5.2.3.2.  Example

   The Recurrence Rule property ("RECUR") of [RFC5545] defines its value
   to be a MAP.

   In vObject notation its value type is defined to be:












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   MAP(
     KEYVALUE(FREQ, TEXT),
     KEYVALUE(UNTIL, ISO-DATE-COMPLETE / ISO-DATE-TIME-BASIC),
     KEYVALUE(COUNT, INTEGER),
     KEYVALUE(INTERVAL, INTEGER),
     KEYVALUE(BYSECOND, LIST(INTEGER)),
     KEYVALUE(BYMINUTE, LIST(INTEGER)),
     KEYVALUE(BYHOUR, LIST(INTEGER)),
     KEYVALUE(BYDAY, LIST(INTEGER)),
     KEYVALUE(BYMONTHDAY, LIST(INTEGER)),
     KEYVALUE(BYYEARDAY, LIST(INTEGER)),
     KEYVALUE(BYWEEKNO, LIST(INTEGER)),
     KEYVALUE(BYMONTH, LIST(INTEGER)),
     KEYVALUE(BYSETPOS, INTEGER),
     KEYVALUE(WKST, TEXT)
   )

5.2.3.3.  Normalizing a MAP

   When normalizing a MAP, each value of it *MUST* be normalized, and
   the values *MUST* be sorted alphabetically according to its "key".

5.3.  Basic Value Types

5.3.1.  TEXT

   This corresponds to the TEXT value type in 4.1 [RFC6350] and 3.3.11
   [RFC5545].

5.3.1.1.  Value Type Notation

   TEXT

5.3.1.2.  Purpose

   This value type defines values that contain free-form, human-readable
   text.

5.3.1.3.  Format Definition

   text = VALUE-CHAR

5.3.1.4.  Associated parameters

   o  Language in which the text is represented can be controlled by the
      "LANGUAGE" property parameter.





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5.3.1.5.  Example

   This multiple line value is a valid value for the NOTE property of
   vCard:

   TC VCARD
   The Calendaring And Scheduling Consortium
   July 20, 2017

5.3.2.  URI

   This corresponds to the URI value type in 4.2 [RFC6350] and 3.3.13
   [RFC5545].

5.3.2.1.  Value Type Notation

   URI

5.3.2.2.  Purpose

   This value type defines values that are represented by data
   referenced by a uniform resource identifier (URI), the value is what
   the URI points to, not the URI itself.

5.3.2.3.  Format Definition

   uri = <As defined in Section 3 of [RFC3986]>

5.3.2.4.  Description

   When a property parameter value is a URI value type, the URI *MUST*
   be specified as a quoted-string value.

5.3.2.5.  Example

   This following values for the PHOTO property of vCard are valid.

   Example 1:

   http://www.example.com/pub/photos/jqpublic.gif

   Example 2:

   data:image/jpeg;base64,MIICajCCAdOgAwIBAgICBEUwDQYJKoZIhv
    AQEEBQAwdzELMAkGA1UEBhMCVVMxLDAqBgNVBAoTI05ldHNjYXBlIENvbW11bm
    ljYXRpb25zIENvcnBvcmF0aW9uMRwwGgYDVQQLExNJbmZvcm1hdGlvbiBTeXN0
    <...remainder of base64-encoded data...>




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5.3.2.6.  Normalization

   No normalization procedures are needed.

5.3.3.  BOOLEAN

   This corresponds to the BOOLEAN value types in 4.4 [RFC6350] and
   3.3.2 [RFC5545].

5.3.3.1.  Value Type Notation

   BOOLEAN

5.3.3.2.  Purpose

   This value type is used to identify properties that contain either a
   "TRUE" or "FALSE" Boolean value.

5.3.3.3.  Format Definition

   boolean = "TRUE" / "FALSE"

5.3.3.4.  Description

   Parsing of "TRUE" and "FALSE" values *SHOULD* be case-insensitive,
   but a writer of such value *MUST* only output of this value type in
   uppercase.

5.3.3.5.  Examples

   o  TRUE

   o  false

   o  True

   o  FaLSe

5.3.3.6.  Normalization

   Values of the BOOLEAN data type *MUST* be normalized to uppercase,
   i.e., the values "TRUE" and "FALSE".

5.3.4.  INTEGER

   The INTEGER-64 and INTEGER-32 value types corresponds to the INTEGER
   value types in 4.5 [RFC6350] and in 3.3.8 [RFC5545] respectively.




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5.3.4.1.  Value Type Notation

   INTEGER

   (INTEGER-32 for storing 32-bit integer, INTEGER-64 for storing 64-bit
   integer)

5.3.4.2.  Purpose

   Representation of a signed integer value.

5.3.4.3.  Format Definition

   integer = (["+"] / "-") 1*DIGIT

5.3.4.4.  Description

   If a preceding sign is not specified, the value is assumed positive
   "".  While the format accepts the optional "" PLUS sign, a writer
   that conforms to this document *SHOULD* not write the "+" sign for
   clarity reasons.

   The valid ranges for INTEGER-32 and INTEGER-64 are:

   o  INTEGER-32: -2147483648 (-2^31) to 2147483647 (2^31 - 1)

   o  INTEGER-64: -9223372036854775807 (-2^63) to 9223372036854775808
      (2^63 - 1)

5.3.4.5.  Examples

   o  1234567890

   o  -1234567890

   o  +1234567890

   o  432109876

5.3.4.6.  Normalization

   A positive integer when normalized *MUST* not have the optional "+"
   sign.








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5.3.5.  FLOAT

   This corresponds to the FLOAT value types in 3.3.7 [RFC5545] and 4.6
   [RFC6350].

5.3.5.1.  Value Type Notation

   FLOAT

5.3.5.2.  Purpose

   Representation of a real-number value.

5.3.5.3.  Format Definition

   float = (["+"] / "-") 1*DIGIT ["." 1*DIGIT]

5.3.5.4.  Description

   If a preceding sign is not specified, the value is assumed positive
   "+".

   Implementations *MUST* support a precision equal or better than that
   of the IEEE "binary64" format [IEEE.754.2008].

   Scientific notation is disallowed.

5.3.5.5.  Examples

   o  20.30

   o  1000000.0000001

   o  1.333

   o  -3.14

5.3.5.6.  Normalization

   No normalization procedures are needed.

   Trailing zeros, such as "100.10000" *MUST* be kept as it indicates
   accuracy of the number.








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5.3.6.  LANGUAGE-TAG

   This corresponds to the LANGUAGE-TAG value type in 4.8 [RFC6350].

5.3.6.1.  Value Type Notation

   LANGUAGE-TAG

5.3.6.2.  Purpose

   Representing a language tag, as defined in [RFC5646].

5.3.6.3.  Format Definition

   Defined in [RFC5646].

5.3.6.4.  Description

   A single language tag

5.3.6.5.  Examples

   o  de

   o  en-US

   o  sr-Cyrl

   o  zh-yue-HK

5.3.6.6.  Normalization

   The normalization procedure of the LANGUAGE-TAG data type follows the
   procedure described in 2.1.1 [RFC5646].

   o  language codes *MUST* be written in lowercase ('mn' Mongolian)

   o  script codes *MUST* be in lowercase when the initial letter
      capitalized ('Cyrl' Cyrillic)

   o  country codes *MUST* be capitalized ('MN' Mongolia)

   As the language tag is comprised of a mixture of these components,
   [RFC5646] provides a rule that applies this procedure across all
   language tags:

   o  All subtags, including extension and private use subtags, *MUST*
      use lowercase letters.



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   o  Except: two-letter subtags that neither appear at the start of the
      tag nor occur after singletons *MUST* be in uppercase ("en-CA-
      x-ca" or "sgn-BE-FR").

   o  Except: four-letter subtags that neither appear at the start of
      the tag nor occur after singletons *MUST* be in titlecase ("az-
      Latn-x-latn").

5.3.7.  Binary

   This corresponds to the BINARY value type in 3.3.1 [RFC5545].

5.3.7.1.  Value Type Notation

   BINARY

5.3.7.2.  Purpose

   This value type defines values that contain inline binary data
   encoded in characters.  For example, an inline "ATTACH" property of
   an iCalendar object or an inline "PHOTO" property image inside a
   vCard object.

5.3.7.3.  Format Definition

   binary = *(4b-char) [b-end]
     ; A "BASE64" encoded character string, as defined by [RFC4648].

   b-end  = (2b-char "==") / (3b-char "=")

   b-char = ALPHA / DIGIT / "+" / "/"

5.3.7.4.  Description

   Property values with this value type *MUST* specify the parameter
   "ENCODING" with parameter value "BASE64", and the inline binary data
   *MUST* be character encoded using the "BASE64" encoding method
   defined in [RFC2045].

5.3.7.5.  Example

   This value for the NOTE value of vCard:

   The following is an example of a "BASE64" encoded binary value data
   folded to 72 characters long:






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AAABAAEAEBAQAAEABAAoAQAAFgAAACgAAAAQAAAAIAAAAAEABAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAACAAAAAgIAAAICAgADAwMAA////AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAMwAAAAAAABNEMQAAAAAAAk
QgAAAAAAJEREQgAAACECQ0QgEgAAQxQzM0E0AABERCRCREQAADRDJEJEQwAAAhA0QwEQAAAA
AEREAAAAAAAAREQAAAAAAAAkQgAAAAAAAAMgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

5.3.8.  KEYVALUE

5.3.8.1.  Value Type Notation

   "KEYVALUE(key, value-type)"

5.3.8.2.  Purpose

   Representation of a key-value pair: a key "key" linked to a value of
   value type "value-type".

5.3.8.3.  Format Definition

   assign-key   = *(TSAFE-CHAR)
   assign-value = prop-values

5.3.8.4.  Description

   This value type is a core component of the "MAP" value type.

   If the "KEYVALUE" value is accepted within a list, the "key" value
   must be unique amongst the list.

5.3.8.5.  Examples

   o  key: "FREQ"; value: "WEEKLY"

   o  key: "BYHOUR"; value: "3,6,9"

   o  key: "BYWEEKNO"; value: "MO,TU,WE,TH,FR,SA"

5.3.8.6.  Normalization

   Its value *MUST* be normalized according to the "value-type" of that
   value.

5.4.  Date and Time Value Types

   These date and time related value types are based on [ISO.8601.2004]
   and [ISO.8601.2000].




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5.4.1.  ISO-DATE-COMPLETE

   This corresponds to the DATE value type in 3.3.4 [RFC5545].

5.4.1.1.  Value Type Notation

   ISO-DATE-COMPLETE

5.4.1.2.  Purpose

   Representation of a complete calendar date defined in
   [ISO.8601.2004].

5.4.1.3.  Format Definition

 iso-date               = iso-date-value
 iso-date-value         = iso-date-fullyear iso-date-month iso-date-mday
 iso-date-fullyear      = 4DIGIT
 iso-date-month         = 2DIGIT   ;01-12
 iso-date-mday          = 2DIGIT   ;01-28, 01-29, 01-30, 01-31
                                   ;based on month/year

5.4.1.4.  Description

   This value format is based on the "basic format" calendar date
   (specified in 4.1.2.2 [ISO.8601.2004] "Complete representations").

   The value *MUST* be represented textually as "YYYYMMDD", with its
   components "YYYY" a four-digit year, "MM" a two-digit month, and "DD"
   a two-digit day of the month as described in the definition.

5.4.1.5.  Example

   The following represents July 1, 1997:

   o  19970701

5.4.1.6.  Normalization

   No normalization procedures are needed.

5.4.2.  ISO-DATE-FLEX

   Representation of a calendar date [ISO.8601.2004] that does not
   require complete representation.

   This corresponds to the DATE value type in 4.3.1 [RFC6350].




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5.4.2.1.  Value Type Notation

   ISO-DATE-FLEX

5.4.2.2.  Purpose

   This value type defines a calendar date format that allows entry of a
   complete calendar date [ISO.8601.2004], a reduced accuracy date
   [ISO.8601.2004] and a truncated date [ISO.8601.2004].

5.4.2.3.  Format Definition

   iso-date-flex   = iso-date /
                     iso-date-reduced /
                     iso-date-truncated

   iso-date-reduced = iso-date-fullyear / iso-date-year-month
   iso-date-year-month = iso-date-fullyear "-" iso-date-month

   iso-date-truncated =  iso-date-truncated-month-day /
                         iso-date-truncated-month-only /
                         iso-date-truncated-day-only

   iso-date-truncated-month-day  = "--" iso-date-month iso-date-mday
   iso-date-truncated-month-only =  "--" iso-date-month
   iso-date-truncated-day-only   =  "---" iso-date-mday

5.4.2.4.  Description

   This value format accepts:

   o  a complete calendar date, specified in 4.1.2.2 [ISO.8601.2004]
      "Complete representations",

   o  a reduced accuracy calendar date, specified in 4.1.2.3
      [ISO.8601.2004] "Representations with reduced accuracy", and

   o  a truncated representation calendar date, specified in 5.2.1.3
      [ISO.8601.2000] "Truncated representations".

   The value can be represented in these ways:

   o  "YYYYMMDD" Complete representation basic format, specified in
      4.1.2.2 [ISO.8601.2004].

   o  "YYYY-MM" Reduced accuracy representation, specified in 4.1.2.3 a)
      [ISO.8601.2004].




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   o  "YYYY" Reduced accuracy representation, specified in 4.1.2.3 b)
      [ISO.8601.2004].

   o  "--MMDD" Truncated representation for a specific day of a month in
      the implied year, basic format, specified in 5.2.1.3 d)
      [ISO.8601.2000].

   o  "--MM" Truncated representation for a specific month in the
      implied year, basic format, specified in 5.2.1.3 e)
      [ISO.8601.2000].

   o  "---DD" Truncated representation for a specific day in the implied
      month, basic format, specified in 5.2.1.3 f) [ISO.8601.2000].

   Example:

   o  20170712

   o  2017-07

   o  2017

   o  --0712

   o  --07

   o  ---12

5.4.2.5.  Normalization

   No normalization procedures are needed.

5.4.3.  ISO-TIME-COMPLETE

   This corresponds to the "time" portion of the TIMESTAMP value type in
   4.3.5 [RFC6350].

5.4.3.1.  Value Type Notation

   ISO-TIME-COMPLETE

5.4.3.2.  Purpose

   Representation of a complete time of day with a UTC offset
   [ISO.8601.2004].






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5.4.3.3.  Format Definition

   iso-time = time-hour time-minute time-second
              [iso-time-utc / iso-utc-offset]

   iso-time-hour    = 2DIGIT        ;00-23
   iso-time-minute  = 2DIGIT        ;00-59
   iso-time-second  = 2DIGIT        ;00-60
   ;The "60" value is used to account for positive "leap" seconds.

   iso-time-utc     = "Z"

5.4.3.4.  Description

   This value format accepts a time of day value specified as:

   o  "hhmmss", the basic format of 4.2.2.2 [ISO.8601.2004] "Complete
      representations".

   o  "hhmmssZ", the first basic format of 4.2.4 [ISO.8601.2004] "UTC of
      day".

   o  "hhmmss+/-hhmm", "hhmmss+/-hh", the basic formats of 4.2.5.2
      [ISO.8601.2004] "Local time and the difference from UTC"

   The components mean: "hh" a two-digit, 24-hour of the day (00-23),
   "mm" a two-digit minute in the hour (00-59), and "ss" a two-digit
   second in the minute (00-60).

   The seconds value of 60 *MUST* only be used to account for positive
   "leap" seconds.  Fractions of a second are not supported by this
   format.

   This value indicates "local time" as specified in 2.1.16
   [ISO.8601.2004].  To indicate UTC time, a "Z" character *MUST* be
   appended to the basic format as described in 4.2.4 [ISO.8601.2004]
   "UTC of day".  To indicate a UTC offset, the "utc-offset" section
   *MUST* be specified in accordance with 4.2.5.2.  [ISO.8601.2004]

   The value of "hhmmssZ" *MUST* be used instead of the equivalent
   "hhmmss+0000" or "hhmmss-0000".

   Example:

   o  140000

   o  140000Z




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   o  140000-05

   o  140000-0500

5.4.3.5.  Normalization

   No normalization procedures are needed.

5.4.4.  ISO-TIME-BASIC

   This corresponds to the TIME value type in 3.3.12 [RFC5545].

5.4.4.1.  Value Type Notation

   ISO-TIME-BASIC

5.4.4.2.  Purpose

   Representation of a complete time of day disallowing a UTC offset
   [ISO.8601.2004].

5.4.4.3.  Format Definition

   iso-time-basic = iso-time-hour iso-time-minute iso-time-second
                    [iso-time-utc]

5.4.4.4.  Description

   This value format is similar to "TIME" except it disallows the
   additional UTC offset, (the basic formats of 4.2.5.2 [ISO.8601.2004]
   "Local time and the difference from UTC").

   This value format accepts a time of day value specified as:

   o  "hhmmss", the basic format of 4.2.2.2 [ISO.8601.2004] "Complete
      representations".

   o  "hhmmssZ", the first basic format of 4.2.4 [ISO.8601.2004] "UTC of
      day".

   The seconds value of 60 *MUST* only be used to account for positive
   "leap" seconds.  Fractions of a second are not supported by this
   format.

   This value indicates "local time" as specified in 2.1.16
   [ISO.8601.2004].  To indicate UTC time, a "Z" character *MUST* be
   appended to the basic format as described in 4.2.4 [ISO.8601.2004]
   "UTC of day".



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   Example:

   o  232050

   o  232050Z

5.4.4.5.  Normalization

   No normalization procedures are needed.

5.4.5.  ISO-TIME-FLEX

   This corresponds to the TIME value type in 4.3.2 [RFC6350].

5.4.5.1.  Value Type Notation

   ISO-TIME-FLEX

5.4.5.2.  Purpose

   This value type defines a time of day format that allows a entry of a
   complete time of day [ISO.8601.2004], a reduced accuracy date
   [ISO.8601.2004] and a truncated date representation [ISO.8601.2000].

5.4.5.3.  Format Definition

  iso-time-flex = iso-time /
                  iso-time-reduced /
                  iso-time-truncated

  iso-time-zone = iso-time-utc / iso-time-utc-offset

  iso-time-reduced =  iso-time-reduced-hour-minute /
                      iso-time-hour

  iso-time-reduced-hour-minute = iso-time-hour iso-time-minute

  iso-time-truncated =  iso-time-truncated-minute-second /
                        iso-time-truncated-minute-only /
                        iso-time-truncated-second-only
  iso-time-truncated-minute-second = "-" iso-time-minute iso-time-second
  iso-time-truncated-minute-only = "-" iso-time-minute
  iso-time-truncated-second-only = "--" iso-time-second








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5.4.5.4.  Description

   This value format accepts:

   o  a complete time of day, specified in 4.2.2.2 [ISO.8601.2004]
      "Complete representations",

   o  a reduced accuracy time of day, specified in 4.2.2.3
      [ISO.8601.2004] "Representations with reduced accuracy",

   o  and a truncated representation time of day, specified in 5.3.1.4
      [ISO.8601.2000] "Truncated representations".

   The value can be represented in these ways:

   o  "hhmmss" Complete representation basic format, specified in
      4.2.2.2 [ISO.8601.2004].

   o  "hhmm" Reduced accuracy representation basic format for a specific
      hour and minute, specified in 4.2.2.3 a) [ISO.8601.2004].

   o  "hh" Reduced accuracy representation basic format for a specific
      hour, specified in 4.2.2.3 b) [ISO.8601.2004].

   o  "-mmss" Truncated representation for a specific minute and second
      of the implied hour, specified in 5.3.1.4 a) [ISO.8601.2000].

   o  "-mm" Truncated representation for a specific minute of the
      implied hour, specified in 5.3.1.4 b) [ISO.8601.2000].

   o  "--ss" Truncated representation for a specific second of the
      implied minute, specified in 5.3.1.4 c) [ISO.8601.2000].

   The seconds value of 60 *MUST* only be used to account for positive
   "leap" seconds.  Fractions of a second are not supported by this
   format.

   This value indicates "local time" as specified in 2.1.16
   [ISO.8601.2004].  To indicate UTC time, a "Z" character *MUST* be
   appended to the basic format as described in 4.2.4 [ISO.8601.2004]
   "UTC of day".

   This format requires the midnight hour to be represented by "00"
   (4.2.3 a) [ISO.8601.2004]), not "24" (4.2.3 b) [ISO.8601.2004]).

   This format supports the specification of UTC offsets for the
   complete representation basic format (defined in 4.2.5.2
   [ISO.8601.2004] basic format), in the form of "hhmmss+/-HHMM".



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   "HHMM" is the hour and minute of UTC offset, defined in 4.2.5.1
   [ISO.8601.2004] basic format.

   Example:

   o  102200

   o  1022

   o  10

   o  -2200

   o  --00

   o  102200Z

   o  102200+0800

5.4.5.5.  Normalization

   No normalization procedures are needed.

5.4.6.  ISO-UTC-OFFSET

   This corresponds to the UTC-OFFSET value type in 4.7 [RFC6350].

5.4.6.1.  Value Type Notation

   ISO-UTC-OFFSET

5.4.6.2.  Purpose

   Representation of a UTC offset as described in [ISO.8601.2004].

5.4.6.3.  Format Definition

   sign = "+" / "-"
   iso-utc-offset = sign iso-time-hour [iso-time-minute]

   Description:

   The value can be represented in two ways:

   o  "+/-hhmm" specified in 4.2.5.1 [ISO.8601.2004] "Difference between
      local time and UTC of day", the first basic format.





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   o  "+/-hh" specified in 4.2.5.1 [ISO.8601.2004] "Difference between
      local time and UTC of day", the second basic format.

   The PLUS SIGN character MUST be specified for positive UTC offsets
   (i.e., ahead of UTC).  The HYPHEN-MINUS character MUST be specified
   for negative UTC offsets (i.e., behind of UTC).

   The value of "-00" and "-0000" are not allowed.  The time-minute, if
   present, MUST NOT be 60; if absent, it defaults to zero.

5.4.6.4.  Example

   The following UTC offsets are given for standard time for New York
   (five hours behind UTC) and Geneva (one hour ahead of UTC):

   o  -05

   o  -0500

   o  +01

   o  +0100

5.4.6.5.  Normalization

   No normalization procedures are needed.

5.4.7.  CAL-UTC-OFFSET

   This corresponds to the UTC-OFFSET value type in 3.3.14 [RFC5545].

5.4.7.1.  Value Type Notation

   CAL-UTC-OFFSET

5.4.7.2.  Purpose

   Representation of a UTC offset as described in [RFC5545].

5.4.7.3.  Format Definition

   cal-utc-offset = sign iso-time-hour iso-time-minute [iso-time-second]

5.4.7.4.  Description:

   The value can be represented in two ways:





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   o  "+/-hhmm" specified in 4.2.5.1 [ISO.8601.2004] "Difference between
      local time and UTC of day", the first basic format.

   o  "+/-hhmmss" which is unique to this value type.

   The PLUS SIGN character MUST be specified for positive UTC offsets
   (i.e., ahead of UTC).  The HYPHEN-MINUS character MUST be specified
   for negative UTC offsets (i.e., behind of UTC).

   The value of "-0000" and "-000000" are not allowed.  The time-second,
   if present, MUST NOT be 60; if absent, it defaults to zero.

5.4.7.5.  Example

   The following UTC offsets are given for standard time for New York
   (five hours behind UTC) and Geneva (one hour ahead of UTC):

   o  -0500

   o  -050000

   o  +0100

   o  +010000

5.4.7.6.  Normalization

   No normalization procedures are needed.

5.4.8.  ISO-DATE-TIME-COMPLETE

   This corresponds to the TIMESTAMP value type in 4.3.5 [RFC6350].

5.4.8.1.  Value Type Notation

   ISO-DATE-TIME-COMPLETE

5.4.8.2.  Purpose

   A complete date and time of day combination as specified in 4.3.2
   [ISO.8601.2004]

5.4.8.3.  Format Definition

   iso-date-time  = iso-date "T" iso-time






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5.4.8.4.  Description

   This value format accepts a complete date and time of day
   representation, specified in 4.3.2 [ISO.8601.2004] "Complete
   representations".

   The value can be represented in these ways:

   o  "YYYYMMDDThhmmss" 4.3.2 Complete representation basic format,
      first entry.

   o  "YYYYMMDDThhmmssZ" 4.3.2 Complete representation basic format,
      second entry.

   o  "YYYYMMDDThhmmss+/-hhmm" 4.3.2 Complete representation basic
      format, third entry.

   o  "YYYYMMDDThhmmss+/-hh" 4.3.2 Complete representation basic format,
      fourth entry.

5.4.8.5.  Examples

   o  19850412T101530

   o  19850412T101530Z

   o  19850412T101530+0400

   o  19850412T101530+04

5.4.8.6.  Normalization

   No normalization procedures are needed.

5.4.9.  ISO-DATE-TIME-BASIC

   This corresponds to the DATE-TIME value type in 3.3.5 [RFC5545].

5.4.9.1.  Value Type Notation

   ISO-DATE-TIME-BASIC

5.4.9.2.  Purpose

   A date and time of day combination without non-UTC timezone as
   specified in 4.3.2 [ISO.8601.2004]





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5.4.9.3.  Format Definition

   iso-date-time-no-zone  = iso-date "T" iso-time-basic

5.4.9.4.  Description

   This value format accepts a complete date and time of day
   representation, specified in 4.3.2 [ISO.8601.2004] "Complete
   representations", identical with ISO-DATE-TIME-COMPLETE, except that
   the "utc-offset" portion is disallowed.

   The value can be represented in these ways:

   o  "YYYYMMDDThhmmss" 4.3.2 Complete representation basic format,
      first entry.

   o  "YYYYMMDDThhmmssZ" 4.3.2 Complete representation basic format,
      second entry.

   Due to the lack of "utc-offset", properties that use this value type
   *SHOULD* handle time zone information with other methods such as in
   property parameters, such as using the "TZID" property parameter
   defined in [RFC5545].

5.4.9.5.  Examples

   o  19980118T230000

   o  19980118T230000Z

5.4.9.6.  Normalization

   No normalization procedures are needed.

5.4.10.  ISO-DATE-TIME-FLEX

   This corresponds to the DATE-TIME value type in 4.3.3 [RFC6350].

5.4.10.1.  Value Type Notation

   DATE-TIME-FLEX

5.4.10.2.  Purpose

   This value type defines a date and time of day combination as
   specified in 4.3 [ISO.8601.2004] and 5.4.2 c [ISO.8601.2000]).





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5.4.10.3.  Format Definition

iso-date-time-flex = iso-date-time-flex-date "T" iso-date-time-flex-time

iso-date-time-flex-date = iso-date / iso-date-truncated
iso-date-time-flex-time = iso-time / iso-time-reduced

5.4.10.4.  Description

   This value format allows for the:

   o  truncation of the date portion and

   o  the reduced accuracy of the time portion

   o  according to the requirements of 5.4.2 [ISO.8601.2000]
      "Representations other than complete" part c).

5.4.10.5.  Examples

   o  19961022T150236

   o  --1022T1502

   o  ---22T15

5.4.10.6.  Normalization

   No normalization procedures are needed.

5.4.11.  ISO-DATE-AND-OR-TIME

   This corresponds to the DATE-AND-OR-TIME value type in 4.3.4
   [RFC6350].

5.4.11.1.  Value Type Notation

   ISO-DATE-AND-OR-TIME

5.4.11.2.  Purpose

   Representation of a ISO-DATE-FLEX, ISO-TIME-FLEX or an ISO-DATE-TIME-
   FLEX value.








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5.4.11.3.  Format Definition

   iso-date-and-or-time = iso-date-flex /
                          "T" iso-time-flex /
                          iso-date-time-flex

5.4.11.4.  Description

   This value format accepts values of ISO-DATE-FLEX, ISO-TIME-FLEX and
   ISO-DATE-TIME-FLEX.

   A stand-alone ISO-TIME value *MUST* be preceded by a "T" for
   unambiguous interpretation.

5.4.11.5.  Example

   o  19961022T140000

   o  --1022T1400

   o  ---22T14

   o  19850412

   o  1985-04

   o  1985

   o  --0412

   o  ---12

   o  T102200

   o  T1022

   o  T10

   o  T-2200

   o  T--00

   o  T102200Z

   o  T102200-0800






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5.4.11.6.  Normalization

   No normalization procedures are needed.

5.4.12.  ISO-DURATION-COMPLETE

   This corresponds to the values accepted by "duration" as specified in
   [ISO.8601.2004].

5.4.12.1.  Value Type Notation

   ISO-DURATION-COMPLETE

5.4.12.2.  Purpose

   Representing a duration of time specified by 4.4.3.2 [ISO.8601.2004]
   complete representation basic format.

5.4.12.3.  Format Definition


   iso-duration-sign = ["+"] / "-"
   iso-duration  = ( iso-duration-sign ) "P" iso-duration-value

   iso-duration-value =  iso-duration-date / iso-duration-week

   iso-duration-date   = iso-duration-day "T" iso-duration-time

   iso-duration-week   = 1*DIGIT "W"

   iso-duration-year   = 1*DIGIT "Y"
   iso-duration-month  = 1*DIGIT "M"
   iso-duration-day    = 1*DIGIT "D"

   iso-duration-time   = iso-duration-hour iso-duration-minute
                         iso-duration-second

   iso-duration-hour   = 1*DIGIT "H"
   iso-duration-minute = 1*DIGIT "M"
   iso-duration-second = 1*DIGIT "S"

5.4.12.4.  Description

   The value format is based on the complete representation basic format
   specified in 4.4.3.2.  [ISO.8601.2004]

   It accepts the following formats ("nn" represents):




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   o  "PnnW" 4.4.3.2 [ISO.8601.2004], complete representation, first
      basic format, for duration in weeks.

   o  "PnnYnnMnnDTnnHnnMnnS" 4.4.3.2 [ISO.8601.2004], complete
      representation, second basic format, for duration in years,
      months, days, hours, minutes and seconds.

   This format differs from the specification of 4.4.3.2 [ISO.8601.2004]
   in the following areas:

   o  An optional, preceding "sign", element is used to indicate
      positive or negative duration.  Negative durations are useful in
      representing reverse scheduling, such as the time to trigger an
      alarm before an associated time (see [RFC5545]).

   o  Reduced accuracy as defined in 4.4.3.2 [ISO.8601.2004] is not
      allowed.  Omission of the number and corresponding designator of
      days, hours, minutes or seconds is not allowed even if any of the
      expressions are zero (4.4.3.2 [ISO.8601.2004] c)).

   o  The duration of a week or a day depends on its position in the
      calendar.

   In the case of discontinuities in the time scale, such as the change
   from standard time to daylight time and back, the computation of the
   exact duration requires the subtraction or addition of the change of
   duration of the discontinuity.  Leap seconds *MUST NOT* be considered
   when computing an exact duration.

5.4.12.5.  Examples

   A duration of 15 days, 5 hours, and 20 seconds *MAY* be represented
   as

   o  P0Y0M15DT5H0M20S

   A duration of 7 weeks *MAY* be represented as:

   o  P7W

5.4.12.6.  Normalization

   No normalization procedures are needed.








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5.4.13.  CAL-DURATION

   This corresponds to the DURATION value type in 3.3.6 [RFC5545].

5.4.13.1.  Value Type Notation

   CAL-DURATION

5.4.13.2.  Purpose

   Representing a duration of time specified by 4.4.3.2 [ISO.8601.2004]
   complete representation basic format, similar to ISO-DURATION, but
   with syntax tailored to calendaring.

5.4.13.3.  Format Definition

   cal-duration         = cal-duration-sign cal-duration-no-sign
   cal-duration-sign    = (["+"] / "-")
   cal-duration-no-sign = "P" cal-duration-value

   cal-duration-value   = ( cal-duration-date /
                            cal-duration-time /
                            cal-duration-week )

   cal-duration-date   = cal-duration-day [cal-duration-time]

   cal-duration-time   = "T" ( cal-duration-hour /
                               cal-duration-minute /
                               cal-duration-second )

   cal-duration-week   = 1*DIGIT "W"
   cal-duration-hour   = 1*DIGIT "H" [cal-duration-minute]
   cal-duration-minute = 1*DIGIT "M" [cal-duration-second]
   cal-duration-second = 1*DIGIT "S"
   cal-duration-day    = 1*DIGIT "D"

5.4.13.4.  Description

   The value format is similar to ISO-DURATION and based on the complete
   representation basic format specified in 4.4.3.2 [ISO.8601.2004], but
   given extra flexibility to calendaring usage.

   It accepts the following formats ("nn" represents):

   o  "PnnW" 4.4.3.2 [ISO.8601.2004], complete representation, first
      basic format, for duration in weeks.





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   o  "PnnDTnnHnnMnnS" 4.4.3.2 [ISO.8601.2004], complete representation,
      second basic format, with the omission of years and months, for
      duration in days, hours, minutes and seconds.

   o  "PnnDTnnHnnM" Reduced accuracy with omission of seconds.

   o  "PnnDTnnH" Reduced accuracy with omission of minutes.

   o  "PnnD" Reduced accuracy with omission of hours.

   This format differs from the specification of 4.4.3.2 [ISO.8601.2004]
   in the following areas:

   o  Years and months are not accepted in this syntax.

   o  An optional, preceding "sign", element is used to indicate
      positive or negative duration.  Negative durations are useful in
      representing reverse scheduling, such as the time to trigger an
      alarm before an associated time (see [RFC5545]).

   o  Reduced accuracy is allowed for in particular, the omission of the
      number and designators of hours, minutes or seconds is allowed
      with the omission starting from the extreme right-hand side.  In
      the case of the omission of the time value, the "T" separator
      *MUST* also be omitted.  The day ("D") portion *MUST* always be
      present.

   o  The duration of a week or a day depends on its position in the
      calendar.

   In the case of discontinuities in the time scale, such as the change
   from standard time to daylight time and back, the computation of the
   exact duration requires the subtraction or addition of the change of
   duration of the discontinuity.  Leap seconds *MUST NOT* be considered
   when computing an exact duration.

   When computing an exact duration, the greatest order time components
   *MUST* be added first, that is, the number of days *MUST* be added
   first, followed by the number of hours, number of minutes, and number
   of seconds.

5.4.13.5.  Example

   A duration of 0 days, 0 hours, and 20 seconds *SHOULD* be represented
   as

   P0DT0H0M20S




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   A duration of 15 days, 5 hours, and 3 hours *SHOULD* be represented
   as

   P15DT5H3M

   A duration of 15 days, 5 hours *SHOULD* be represented as

   P15DT5H

   A duration of 15 days *SHOULD* be represented as

   P15D

   A duration of 7 weeks *SHOULD* be represented as:

   P7W

5.4.13.6.  Normalization

   No normalization procedures are needed.

5.4.14.  ISO-INTERVAL

   This corresponds to the values accepted by "time interval" as
   specified in [ISO.8601.2004].

5.4.14.1.  Value Type Notation

   ISO-INTERVAL-COMPLETE

5.4.14.2.  Purpose

   Representation of a time interval.

5.4.14.3.  Format Definition

   iso-interval     = iso-interval-explicit / iso-interval-start

   iso-interval-explicit = iso-date-time "/" iso-date-time
   iso-interval-start    = iso-date-time "/" iso-duration-no-sign

5.4.14.4.  Description

   This value format accepts a time interval representation, specified
   in 4.4 [ISO.8601.2004] "Time Interval".

   The value can be represented by:




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   a) a start and an end;

   o  "YYYYMMDDThhmmss/YYYYMMDDThhmmss" 4.4.4.1 [ISO.8601.2004] Complete
      representation, "Representations of time intervals identified by
      start and end", basic format, first entry.  The start *MUST* be
      before the end.

   c) a start and a duration;

   o  "YYYYMMDDThhmmss/PnnYnnMnnDTnnHnnMnnS" 4.4.4.3 [ISO.8601.2004]
      Complete representation, "Representations of time interval
      identified by start and duration", first basic format.  The
      duration component *MUST* be positive.

   o  "YYYYMMDDThhmmss/PnnW" 4.4.4.5 [ISO.8601.2004] Other complete
      representations, third item, allowing the expression
      "PnnYnnMnnDTnnHnnMnnS" to be substituted with "PnnW" 4.4.3.2
      [ISO.8601.2004].

   d) a duration and an end.

   o  "PnnYnnMnnDTnnHnnMnnS/YYYYMMDDThhmmss" 4.4.4.4 [ISO.8601.2004]
      Complete representation, "Representations of time interval
      identified by duration and end", first basic format.  The start of
      the interval can be determined by subtracting the duration
      component from the end of the interval.

   o  "PnnW/YYYYMMDDThhmmss" 4.4.4.5 [ISO.8601.2004] Other complete
      representations, third item, allowing the expression
      "PnnYnnMnnDTnnHnnMnnS" to be substituted with "PnnW" 4.4.3.2
      [ISO.8601.2004].

   In accordance with 4.4.4.5 [ISO.8601.2004]:

   o  where representations using local time in a time point component
      are shown, a complete representation of UTC (4.2.4
      [ISO.8601.2004]) or local time and the difference from UTC
      (4.2.5.2 [ISO.8601.2004]) *MAY* be substituted for local time,
      i.e. representations using the expression "YYYYMMDDThhmmss" could
      be substituted with any of these:

   o  "YYYYMMDDThhmmssZ" 4.3.2 Complete representation basic format,
      second entry.

   o  "YYYYMMDDThhmmss+/-hhmm" 4.3.2 Complete representation basic
      format, third entry.





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   o  "YYYYMMDDThhmmss+/-hh" 4.3.2 [ISO.8601.2004] Complete
      representation basic format, fourth entry.

   In accordance with 4.4.5 [ISO.8601.2004]:

   o  representations for UTC included with the component preceding the
      solidus shall be assumed to apply to the component following the
      solidus, unless a corresponding alternative is included.

5.4.14.5.  Examples

   o  19850412T232050/P1Y2M15DT12H30M0S

   o  19850412T232050Z/P1Y2M15DT12H30M0S

   o  19850412T232050Z/19850612T232050

   o  P1Y2M15DT12H30M0S/19850412T232050

5.4.14.6.  Normalization

   No normalization procedures are needed.

5.4.15.  CAL-INTERVAL

   This corresponds to the PERIOD value type in 3.3.9 [RFC5545].

5.4.15.1.  Value Type Notation

   CAL-INTERVAL

5.4.15.2.  Purpose

   Representation of a time interval for calendaring.

5.4.15.3.  Format Definition

 cal-interval     = cal-interval-explicit / cal-interval-start

 cal-interval-explicit = iso-date-time-no-zone "/" iso-date-time-no-zone
 cal-interval-start    = iso-date-time-no-zone "/" cal-duration-no-sign

5.4.15.4.  Description

   This value format accepts a time interval representation, specified
   in 4.4.  [ISO.8601.2004] "Time Interval" tailored for calendaring
   purposes.




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   The value can be represented in two ways.

   As an interval with start and end:

   o  "YYYYMMDDThhmmss/YYYYMMDDThhmmss" 4.4.4.1 [ISO.8601.2004] Complete
      representation, "Representations of time intervals identified by
      start and end", basic format, first entry.  The start *MUST* be
      before the end.

   As an interval with start and duration (positive duration only):

   o  "YYYYMMDDThhmmss/PnnDTnnHnnMnnS" 4.4.4.3 [ISO.8601.2004] Complete
      representation, "Representations of time interval identified by
      start and duration", first basic format, modified to omit the
      "nnYnnM", which is the "cal-duration" period format.

   o  "YYYYMMDDThhmmss/PnnW" 4.4.4.5 [ISO.8601.2004] Other complete
      representations, third item, allowing the expression
      "PnnYnnMnnDTnnHnnMnnS" to be substituted with "PnnW" 4.4.3.2
      [ISO.8601.2004].

   o  "YYYYMMDDThhmmss/PnnDTnnHnnM" with the duration specified in
      reduced accuracy with omission of seconds as in Section 5.4.13.

   o  "YYYYMMDDThhmmss/PnnDTnnH" with the duration specified in reduced
      accuracy with omission of minutes as in Section 5.4.13.

   o  "YYYYMMDDThhmmss/PnnD" with the duration specified in reduced
      accuracy with omission of hours as in Section 5.4.13.

   In accordance with 4.4.5 [ISO.8601.2004], representations for UTC
   included with the component preceding the solidus shall be assumed to
   apply to the component following the solidus, unless a corresponding
   alternative is included.

5.4.15.5.  Examples

   o  19970101T180000Z/19970102T070000Z

   o  19850412T232050/19850625T103000

   o  19970101T180000Z/PT5H30M

   o  19850412T232050/P15DT12H30M0S

   o  19850412T232050/P00010215T123000

   o  Both components are in UTC: 19850412T232050Z/19850625T103000



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   o  Former component in local time, latter in UTC:
      19850412T232050/19850625T103000

5.4.15.6.  Normalization

   No normalization procedures are needed.

6.  Normalization

   A normalization procedure can be applied to vObjects (in its various
   representations) to make them compatible prior to comparison,
   allowing for consistent results.  The result of normalization
   processing of a vObject, is an equivalent vObject described according
   to vFormat representation.

   The normalization method has the following properties:

   o  stable across different implementations generating the same output
      from the same input

   o  compatible with alternative representation formats such as xCard
      [RFC6351] / jCard [RFC7095] and xCal [RFC6321] / jCal [RFC7265]

   o  generates output adhering to the original vObject format allowing
      interoperability with existing implementations

   o  generates output compatible with protocols that utilize these
      vObject, such as CardDAV [RFC6352] and CalDAV [RFC4791] systems.

   There are two levels of normalization.

   o  vObject normalization, of values and property parameter values,
      are performed within the vObject data model;

   o  vFormat normalization, of the format syntax itself, is performed
      during serialization of a vObject into vFormat.

6.1.  Approach

   The goals of the normalization procedure are:

   o  A normalized vObject will be a valid vObject in vFormat syntax.
      Therefore the normalization procedure requires knowledge of the
      source specific vObject format.

   o  A normalized vObject is stable across alternative representation
      formats, such as xCal and jCal of iCalendar, and xCard and jCard




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      of vCard.  This allows comparison of vObject content regardless of
      the representation format.

   o  Allows comparison of equivalence of content rather than
      formatting.  E.g., addition of new-lines within a vCard and order
      of listed properties do not affect the resulting normalized form.

   o  A normalized vObject *MUST* maintain validity under the original
      format rules, such as in the case of VCARD [RFC6350] components,
      the "VERSION" property line *MUST* be located immediately after
      the "BEGIN" property line.

6.2.  Steps

   In order to serialize a vObject into normalized vFormat syntax, one
   would directly serialize the vObject data model into vFormat syntax.

   The steps are generally described below.

   1.  Normalize the vObject

       A.  Normalize properties

           i.    Normalize property parameters

                 A.  Normalize property parameter types

                 B.  Normalize property parameter values

                     I.    Sort property parameter values
                           alphabetically.

                     II.   Concatenate property parameter values.

                 C.  Normalize property parameter key: cast to
                     uppercase.

                 D.  Concatenate string form of property parameter key,
                     value type and values.

           ii.   Normalize property values

       B.  Normalize inner vObjects (sub-components)

           i.   Perform the same function as (1)






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6.3.  Application on alternative serializations

   The normalization procedure applies to alternative vObject
   representations as well, including:

   o  xCard [RFC6351]

   o  jCard [RFC7095]

   o  xCal [RFC6321]

   o  jCal [RFC7265]

   To normalize a vObject provided in these representations, the vObject
   data should be first normalized in data model form according to
   Section 3, and then serialized into these representations.

7.  Client Implementations Recommendations

   A CUA *SHOULD* normalize the vObject upon modification of it.

8.  CardDAV

8.1.  Additional Server Semantics for PUT, COPY and MOVE

   This specification creates an additional precondition and
   postcondition for the PUT, COPY, and MOVE methods when:

   o  A PUT operation requests an address object resource to be placed
      into an address book collection; and

   o  A COPY or MOVE operation requests an address object resource to be
      placed into (or out of) an address book collection.

8.1.1.  Provide Normalized Output

   Certain servers perform silent changes or cleanups of client provided
   vCard data when stored as address object resources, such as the order
   of property parameters or scrubbed values.

   The resulting vCard data stored on the server (and when returned back
   to the client) *MAY* end up different than that of the client without
   its knowledge.  It is therefore necessary for the client to be
   reported on such modifications.

   Additional Postcondition:

   (CARDDAV:resource-normalized): Convert to normalized format.



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9.  CalDAV

9.1.  Additional Server Semantics for PUT, COPY and MOVE

   This specification creates an additional precondition and
   postcondition for the PUT, COPY, and MOVE methods when:

   o  A PUT operation of a calendar object resource into a calendar
      collection occurs [RFC4791];

   o  A COPY or MOVE operation of a calendar object resource into a
      calendar collection occurs [RFC4791]; and

   o  A COPY or MOVE operation occurs on a calendar collection
      [RFC4791].

9.1.1.  Provide Normalized Output

   Certain servers perform silent changes or cleanups of client provided
   iCalendar data when stored as calendar object resources, such as the
   order of property parameters or scrubbed values.

   The resulting iCalendar data stored on the server (and when returned
   back to the client) *MAY* end up different than that of the client
   without its knowledge.  It is therefore necessary for the client to
   be reported on such modifications.

   Additional Postcondition:

   (CALDAV:resource-normalized): Convert to normalized format.

10.  Security Considerations

   Security considerations around vObject formats in the following
   documents *MUST* be adhered to:

   o  vCard: [RFC6350]

   o  iCalendar: [RFC5545], [RFC5789], [RFC4791]

11.  IANA Considerations

   New vObject and vFormat specifications produced *MUST* adhere to the
   requirements, including the normalization process, described in this
   document, and any exceptions or further instructions for
   normalization *MUST* be described.





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11.1.  Common vObject Registries

   The IANA has created and will maintain the following registries for
   vObject elements with pointers to appropriate reference documents.
   The registries are grouped together under the heading "vObject Common
   Elements".

11.2.  vObject Component Uniqueness Identifiers Registry

11.2.1.  Registration Procedure

   This section defines the process to register new or modified
   uniqueness properties for vObject components with IANA.

   The IETF will create a mailing list, vobject@ietf.org, which can be
   used for public discussion of vObject elements prior to registration.

   The registry policy is *Specification Required*; any newly proposed
   specification *MUST* be reviewed by the designated expert.

   The registry *SHOULD* contain the following note:

   Note: Experts are to verify that the proposed registration
   *SHOULD* provide benefits for the wider vObject community,
   and provides a publicly-available standard that can be implemented in
   an interoperable way. References to IETF-published documents are
   preferred. The "Reference" value should point to a document that
   details the implementation of this property.

   The registration procedure begins when a completed registration
   template, defined in the sections below, is sent to vobject@ietf.org
   and iana@iana.org.

   The designated expert is expected to tell IANA and the submitter of
   the registration within two weeks whether the registration is
   approved, approved with minor changes, or rejected with cause.  When
   a registration is rejected with cause, it can be re-submitted if the
   concerns listed in the cause are addressed.  Decisions made by the
   designated expert can be appealed to the IESG Applications Area
   Director, then to the IESG.  They follow the normal appeals procedure
   for IESG decisions.

11.2.2.  Registration Template

   A registration for a vObject Component Uniqueness Property is defined
   by completing the following template.

   Component



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      The name of the component.

   Property
      The property of the component that is used to uniquely identify
      the component it belongs to.

   Scope
      The uniqueness scope of the aforementioned property.

   Reference
      The document that defines the component syntax and the uniqueness
      identifying property.  Generally, this is where the component was
      originally defined, but if the uniqueness property is defined in
      an extension document, a reference to the extension document
      *SHOULD* be given instead.

   Description
      Any special notes about the usage of the uniqueness identifying
      property, how it is to be used, etc.

   Example(s)
      One or more examples of instances of the component need to be
      specified.

11.2.3.  Initial Registrations

   The IANA created and maintains this registry for vObject Component
   Uniqueness Identifiers with pointers to appropriate reference
   documents.

   The following table has been used to initialize the registry.




















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   +--------------+-------------+--------+-----------------------------+
   | Component    | Property    | Scope  | Reference                   |
   +--------------+-------------+--------+-----------------------------+
   | VCALENDAR    | UID         | Global | 5.3 [RFC7986]               |
   | VCARD        | UID         | Global | 6.7.6 [RFC6350]             |
   | VEVENT       | UID         | Global | 3.6.1 [RFC5545]             |
   | VTODO        | UID         | Global | 3.6.2 [RFC5545]             |
   | VJOURNAL     | UID         | Global | 3.6.3 [RFC5545]             |
   | VFREEBUSY    | UID         | Global | 3.6.4 [RFC5545]             |
   | VTIMEZONE    | TZID        | Global | 3.6.5 [RFC5545]             |
   | STANDARD     | DTSTART     | Parent | 3.6.5 [RFC5545]             |
   | DAYLIGHT     | DTSTART     | Parent | 3.6.5 [RFC5545]             |
   | VALARM       | UID         | Global | 4 [I-D.daboo-valarm-extensi |
   |              |             |        | ons]                        |
   | VAVAILABILIT | UID         | Global | 3.1 [RFC7953]               |
   | Y            |             |        |                             |
   | AVAILABLE    | UID         | Global | 3.1 [RFC7953]               |
   | VPOLL        | UID         | Parent | 4.5.1 [I-D.york-vpoll]      |
   | VVOTER       | VOTER       | Parent | 4.5.2 [I-D.york-vpoll]      |
   | VOTE         | POLL-ITEM-  | Parent | 4.5.3 [I-D.york-vpoll]      |
   |              | ID          |        |                             |
   +--------------+-------------+--------+-----------------------------+

12.  Mapping Of Data Value Types For Existing RFCs

   The vObject value types in this section are described using vObject
   value type notation (see Section 5.1).

12.1.  RFC 6350

              +----------------------+---------------------+
              | vObject Value Type   | Original Value Type |
              +----------------------+---------------------+
              | BOOLEAN              | BOOLEAN             |
              | ISO-DATE-FLEX        | DATE                |
              | ISO-DATE-AND-OR-TIME | DATE-AND-OR-TIME    |
              | ISO-DATE-TIME-FLEX   | DATE-TIME           |
              | FLOAT                | FLOAT               |
              | INTEGER-64           | INTEGER             |
              | LANGUAGE-TAG         | LANGUAGE-TAG        |
              | TEXT                 | TEXT                |
              | ISO-TIME-FLEX        | TIME                |
              | ISO-TIME-COMPLETE    | TIMESTAMP           |
              | URI                  | URI                 |
              | ISO-UTC-OFFSET       | UTC-OFFSET          |
              +----------------------+---------------------+





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12.2.  RFC 5545

            +---------------------------+---------------------+
            | vObject Value Type        | Original Value Type |
            +---------------------------+---------------------+
            | BINARY                    | BINARY              |
            | BOOLEAN                   | BOOLEAN             |
            | URI                       | CAL-ADDRESS         |
            | ISO-DATE-COMPLETE         | DATE                |
            | ISO-DATE-TIME-BASIC       | DATE-TIME           |
            | CAL-DURATION              | DURATION            |
            | FLOAT                     | FLOAT               |
            | INTEGER-32                | INTEGER             |
            | CAL-DURATION              | PERIOD              |
            | TEXT                      | TEXT                |
            | ISO-TIME-BASIC            | TIME                |
            | URI                       | URI                 |
            | CAL-UTC-OFFSET            | UTC-OFFSET          |
            | RECURMAP (Section 12.2.1) | RECUR               |
            +---------------------------+---------------------+

12.2.1.  RECURMAP

   RECURMAP is shown here instead of within the tables due to space
   constraints.

   It is defined to be the value type of the following vObject value
   type:

   RECURMAP = MAP(
     KEYVALUE(FREQ, TEXT),
     KEYVALUE(UNTIL, ISO-DATE-COMPLETE / ISO-DATE-TIME-BASIC),
     KEYVALUE(COUNT, INTEGER),
     KEYVALUE(INTERVAL, INTEGER),
     KEYVALUE(BYSECOND, LIST(INTEGER)),
     KEYVALUE(BYMINUTE, LIST(INTEGER)),
     KEYVALUE(BYHOUR, LIST(INTEGER)),
     KEYVALUE(BYDAY, LIST(INTEGER)),
     KEYVALUE(BYMONTHDAY, LIST(INTEGER)),
     KEYVALUE(BYYEARDAY, LIST(INTEGER)),
     KEYVALUE(BYWEEKNO, LIST(INTEGER)),
     KEYVALUE(BYMONTH, LIST(INTEGER)),
     KEYVALUE(BYSETPOS, INTEGER),
     KEYVALUE(WKST, TEXT)
   )






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13.  Mapping Of Component Property Value Types For Existing RFCs

   The default and alternative value types in this section are described
   using vObject value type notation (see Section 5.1).

13.1.  VCARD Component (RFC 6350)

   Properties with the default data type as TEXT.

   +-----------+-------------------+--------------+--------------------+
   | Property  | Default Value     | Alt. Value   | Original Value     |
   |           | Type              | Types        | Type               |
   +-----------+-------------------+--------------+--------------------+
   | BEGIN     | TEXT              |              | 1\*TEXT            |
   | END       | TEXT              |              | 1\*TEXT            |
   | KIND      | TEXT              |              | 1\*TEXT            |
   | XML       | TEXT              |              | 1\*TEXT            |
   | FN        | TEXT              |              | 1\*TEXT            |
   | BDAY      | ISO-DATE-AND-OR-  | TEXT         | 1\*date-and-or-    |
   |           | TIME              |              | time, 1\*text      |
   | ANNIVERSA | ISO-DATE-AND-OR-  | TEXT         | 1\*date-and-or-    |
   | RY        | TIME              |              | time, 1\*text      |
   | EMAIL     | TEXT              |              | 1\*TEXT,           |
   | TZ        | TEXT              | URI, ISO-    | 1\*TEXT, URI, UTC- |
   |           |                   | UTC-OFFSET   | OFFSET             |
   | TITLE     | TEXT              |              | 1\*TEXT            |
   | ROLE      | TEXT              |              | 1\*TEXT            |
   | NOTE      | TEXT              |              | 1\*TEXT            |
   | PRODID    | TEXT              |              | 1\*TEXT            |
   | VERSION   | TEXT              |              | 1\*TEXT            |
   +-----------+-------------------+--------------+--------------------+

   Properties with the default data type as URI.


















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   +-----------+-----------------+-----------------+-------------------+
   | Property  | Default Value   | Alt. Value      | Original Value    |
   |           | Type            | Types           | Type              |
   +-----------+-----------------+-----------------+-------------------+
   | TEL       | URI             | TEXT            | 1\*text, URI      |
   | SOURCE    | URI             |                 | URI               |
   | PHOTO     | URI             |                 | URI               |
   | IMPP      | URI             |                 | URI               |
   | GEO       | URI             |                 | URI               |
   | LOGO      | URI             |                 | URI               |
   | MEMBER    | URI             |                 | URI               |
   | RELATED   | URI             | TEXT            | URI, 1\*text      |
   | UID       | URI             |                 | URI, 1\*text      |
   | KEY       | URI             |                 | URI, 1\*text      |
   | SOUND     | URI             |                 | URI               |
   | URL       | URI             |                 | URI               |
   | FBURL     | URI             |                 | URI               |
   | CALADRURI | URI             |                 | URI               |
   | CALURI    | URI             |                 | URI               |
   +-----------+-----------------+-----------------+-------------------+

   Properties with FIELDSET.

   +--------------+-------------------------+-----------+--------------+
   | Property     | Default Value Type      | Alt.      | Original     |
   |              |                         | Value     | Value Type   |
   |              |                         | Types     |              |
   +--------------+-------------------------+-----------+--------------+
   | N            | FIELDSET(5\*LIST(TEXT)) |           | TEXT         |
   | GENDER       | FIELDSET(2\*TEXT)       |           | TEXT         |
   | ADR          | FIELDSET(7\*LIST(TEXT)) |           | TEXT         |
   | ORG          | FIELDSET(1\*TEXT)       |           | TEXT         |
   | CLIENTPIDMAP | FIELDSET(INTEGER-64,    |           | TEXT         |
   |              | URI)                    |           |              |
   +--------------+-------------------------+-----------+--------------+

   Properties with LIST.

   +------------+------------------+----------------+------------------+
   | Property   | Default Value    | Alt. Value     | Original Value   |
   |            | Type             | Types          | Type             |
   +------------+------------------+----------------+------------------+
   | NICKNAME   | LIST(TEXT)       |                | TEXT             |
   | CATEGORIES | LIST(TEXT)       |                | TEXT             |
   +------------+------------------+----------------+------------------+

   Properties with ISO-DATE-AND-OR-TIME.




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   +-------------+----------------------+----------+-------------------+
   | Property    | Default Value Type   | Alt.     | Original Value    |
   |             |                      | Value    | Type              |
   |             |                      | Types    |                   |
   +-------------+----------------------+----------+-------------------+
   | BDAY        | ISO-DATE-AND-OR-TIME | TEXT     | date-and-or-time, |
   |             |                      |          | text              |
   | ANNIVERSARY | ISO-DATE-AND-OR-TIME | TEXT     | date-and-or-time, |
   |             |                      |          | text              |
   +-------------+----------------------+----------+-------------------+

   Properties with ISO-DATE-TIME-COMPLETE.

   +----------+------------------------+-------------+-----------------+
   | Property | Default Value Type     | Alt. Value  | Original Value  |
   |          |                        | Types       | Type            |
   +----------+------------------------+-------------+-----------------+
   | REV      | ISO-DATE-TIME-COMPLETE |             | timestamp       |
   +----------+------------------------+-------------+-----------------+

   Properties with LANGUAGE-TAG.

   +----------+-------------------+---------------+--------------------+
   | Property | Default Value     | Alt. Value    | Original Value     |
   |          | Type              | Types         | Type               |
   +----------+-------------------+---------------+--------------------+
   | LANG     | LANGUAGE-TAG      |               | language-tag       |
   +----------+-------------------+---------------+--------------------+

13.2.  VCALENDAR Component (RFC 5545)

   +---------------+-----------------+---------------+-----------------+
   | Property      | Default Value   | Alt. Value    | Original Value  |
   |               | Type            | Types         | Type            |
   +---------------+-----------------+---------------+-----------------+
   | PRODID        | TEXT            |               | 1\*TEXT         |
   | VERSION       | TEXT            |               | 1\*TEXT         |
   | CALSCALE      | TEXT            |               | 1\*TEXT         |
   | METHOD        | TEXT            |               | 1\*TEXT         |
   | IANA-REGed/X- | TEXT            |               | 1\*TEXT         |
   +---------------+-----------------+---------------+-----------------+

13.3.  VEVENT Component (RFC 5545)

   +--------------+-------------------+------------------+-------------+
   | Property     | Default Value     | Alt. Value Types | Original    |
   |              | Type              |                  | Value Type  |
   +--------------+-------------------+------------------+-------------+



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   | DTSTAMP      | ISO-DATE-TIME-    |                  | DATE-TIME   |
   |              | BASIC             |                  |             |
   | UID          | TEXT              |                  | 1\*TEXT     |
   | DTSTART      | ISO-DATE-TIME-    | ISO-DATE-        | DATE-TIME,  |
   |              | BASIC             | COMPLETE         | DATE        |
   | CLASS        | TEXT              |                  | 1\*TEXT     |
   | CREATED      | ISO-DATE-TIME-    |                  | DATE-TIME   |
   |              | BASIC             |                  |             |
   | DESCRIPTION  | TEXT              |                  | 1\*TEXT     |
   | GEO          | FIELDSET(2\*FLOAT |                  | FLOAT ";"   |
   |              | )                 |                  | FLOAT       |
   | LAST-        | ISO-DATE-TIME-    |                  | DATE-TIME   |
   | MODIFIED     | BASIC             |                  |             |
   | LOCATION     | TEXT              |                  | 1\*TEXT     |
   | ORGANIZER    | URI               |                  | cal-address |
   | PRIORITY     | INTEGER-32        |                  | INTEGER     |
   | SEQUENCE     | INTEGER-32        |                  | INTEGER     |
   | STATUS       | TEXT              |                  | 1\*TEXT     |
   | SUMMARY      | TEXT              |                  | 1\*TEXT     |
   | TRANSP       | TEXT              |                  | 1\*TEXT     |
   | URL          | URI               |                  | URI         |
   | RECURRENCE-  | ISO-DATE-TIME-    | ISO-DATE-        | DATE-TIME,  |
   | ID           | BASIC             | COMPLETE         | DATE        |
   | RRULE        | RECURMAP (Section |                  | RECUR       |
   |              | 12.2.1)           |                  |             |
   | DTEND        | ISO-DATE-TIME-    | ISO-DATE-        | DATE-TIME,  |
   |              | BASIC             | COMPLETE         | DATE        |
   | DURATION     | DURATION          |                  | DURATION    |
   | ATTACH       | URI               | BINARY           | URI, BINARY |
   | ATTENDEE     | URI               |                  | cal-address |
   | CATEGORIES   | LIST(TEXT)        |                  | TEXT        |
   | COMMENT      | TEXT              |                  | 1\*TEXT     |
   | CONTACT      | TEXT              |                  | 1\*TEXT     |
   | EXDATE       | LIST( ISO-DATE-   |                  | DATE-TIME,  |
   |              | TIME-BASIC / ISO- |                  | DATE        |
   |              | DATE-COMPLETE )   |                  |             |
   | RELATED-TO   | TEXT              |                  | 1\*TEXT     |
   | RESOURCES    | LIST(TEXT)        |                  | TEXT        |
   | RDATE        | LIST( ISO-DATE-   |                  | DATE-TIME,  |
   |              | TIME-BASIC / ISO- |                  | DATE,       |
   |              | DATE-COMPLETE /   |                  | PERIOD      |
   |              | CAL-INTERVAL)     |                  |             |
   | IANA-        | TEXT              |                  | 1\*TEXT     |
   | REGed/X-     |                   |                  |             |
   +--------------+-------------------+------------------+-------------+






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13.4.  VTODO Component (RFC 5545)

   +--------------+-------------------+------------------+-------------+
   | Property     | Default Value     | Alt. Value Types | Original    |
   |              | Type              |                  | Value Type  |
   +--------------+-------------------+------------------+-------------+
   | DTSTAMP      | ISO-DATE-TIME-    |                  | DATE-TIME   |
   |              | BASIC             |                  |             |
   | UID          | TEXT              |                  | 1\*TEXT     |
   | CLASS        | TEXT              |                  | 1\*TEXT     |
   | CREATED      | ISO-DATE-TIME-    |                  | DATE-TIME   |
   |              | BASIC             |                  |             |
   | COMPLETED    | ISO-DATE-TIME-    |                  | DATE-TIME   |
   |              | BASIC             |                  |             |
   | DESCRIPTION  | TEXT              |                  | 1\*TEXT     |
   | DTSTART      | ISO-DATE-TIME-    | ISO-DATE-        | DATE-TIME,  |
   |              | BASIC             | COMPLETE         | DATE        |
   | GEO          | FIELDSET(2\*FLOAT |                  | FLOAT ";"   |
   |              | )                 |                  | FLOAT       |
   | LAST-        | ISO-DATE-TIME-    |                  | DATE-TIME   |
   | MODIFIED     | BASIC             |                  |             |
   | LOCATION     | TEXT              |                  | 1\*TEXT     |
   | ORGANIZER    | URI               |                  | cal-address |
   | PRIORITY     | INTEGER-32        |                  | INTEGER     |
   | SEQUENCE     | INTEGER-32        |                  | INTEGER     |
   | STATUS       | TEXT              |                  | 1\*TEXT     |
   | SUMMARY      | TEXT              |                  | 1\*TEXT     |
   | URL          | URI               |                  | URI         |
   | RRULE        | RECURMAP (Section |                  | RECUR       |
   |              | 12.2.1)           |                  |             |
   | DUE          | ISO-DATE-TIME-    | ISO-DATE-        | DATE-TIME,  |
   |              | BASIC             | COMPLETE         | DATE        |
   | DURATION     | DURATION          |                  | DURATION    |
   | ATTACH       | URI               | BINARY           | URI, BINARY |
   | ATTENDEE     | URI               |                  | cal-address |
   | CATEGORIES   | LIST(TEXT)        |                  | TEXT        |
   | COMMENT      | TEXT              |                  | 1\*TEXT     |
   | CONTACT      | TEXT              |                  | 1\*TEXT     |
   | EXDATE       | LIST( ISO-DATE-   |                  | DATE-TIME,  |
   |              | TIME-BASIC / ISO- |                  | DATE        |
   |              | DATE-COMPLETE )   |                  |             |
   | REQUEST-     | TEXT              |                  | 1\*TEXT     |
   | STATUS       |                   |                  |             |
   | RELATED-TO   | TEXT              |                  | 1\*TEXT     |
   | RESOURCES    | LIST(TEXT)        |                  | TEXT        |
   | RDATE        | LIST( ISO-DATE-   |                  | DATE-TIME,  |
   |              | TIME-BASIC / ISO- |                  | DATE,       |
   |              | DATE-COMPLETE /   |                  | PERIOD      |



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   |              | CAL-INTERVAL)     |                  |             |
   | IANA-        | TEXT              |                  | 1\*TEXT     |
   | REGed/X-     |                   |                  |             |
   +--------------+-------------------+------------------+-------------+

13.5.  VJOURNAL Component (RFC 5545)

   +--------------+-------------------+------------------+-------------+
   | Property     | Default Value     | Alt. Value Types | Original    |
   |              | Type              |                  | Value Type  |
   +--------------+-------------------+------------------+-------------+
   | DTSTAMP      | ISO-DATE-TIME-    |                  | DATE-TIME   |
   |              | BASIC             |                  |             |
   | UID          | TEXT              |                  | 1\*TEXT     |
   | CLASS        | TEXT              |                  | 1\*TEXT     |
   | CREATED      | ISO-DATE-TIME-    |                  | DATE-TIME   |
   |              | BASIC             |                  |             |
   | DTSTART      | ISO-DATE-TIME-    | ISO-DATE-        | DATE-TIME,  |
   |              | BASIC             | COMPLETE         | DATE        |
   | LAST-        | ISO-DATE-TIME-    |                  | DATE-TIME   |
   | MODIFIED     | BASIC             |                  |             |
   | ORGANIZER    | URI               |                  | cal-address |
   | SEQUENCE     | INTEGER-32        |                  | INTEGER     |
   | STATUS       | TEXT              |                  | 1\*TEXT     |
   | SUMMARY      | TEXT              |                  | 1\*TEXT     |
   | URL          | URI               |                  | URI         |
   | RRULE        | RECURMAP (Section |                  | RECUR       |
   |              | 12.2.1)           |                  |             |
   | ATTACH       | URI               | BINARY           | URI, BINARY |
   | ATTENDEE     | URI               |                  | cal-address |
   | CATEGORIES   | LIST(TEXT)        |                  | TEXT        |
   | COMMENT      | TEXT              |                  | 1\*TEXT     |
   | CONTACT      | TEXT              |                  | 1\*TEXT     |
   | DESCRIPTION  | TEXT              |                  | 1\*TEXT     |
   | EXDATE       | LIST( ISO-DATE-   |                  | DATE-TIME,  |
   |              | TIME-BASIC / ISO- |                  | DATE        |
   |              | DATE-COMPLETE )   |                  |             |
   | RELATED-TO   | TEXT              |                  | 1\*TEXT     |
   | RDATE        | LIST( ISO-DATE-   |                  | DATE-TIME,  |
   |              | TIME-BASIC / ISO- |                  | DATE,       |
   |              | DATE-COMPLETE /   |                  | PERIOD      |
   |              | CAL-INTERVAL)     |                  |             |
   | REQUEST-     | TEXT              |                  | 1\*TEXT     |
   | STATUS       |                   |                  |             |
   | IANA-        | TEXT              |                  | 1\*TEXT     |
   | REGed/X-     |                   |                  |             |
   +--------------+-------------------+------------------+-------------+




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13.6.  VFREEBUSY Component (RFC 5545)

   +--------------+-------------------+------------------+-------------+
   | Property     | Default Value     | Alt. Value Types | Original    |
   |              | Type              |                  | Value Type  |
   +--------------+-------------------+------------------+-------------+
   | DTSTAMP      | ISO-DATE-TIME-    |                  | DATE-TIME   |
   |              | BASIC             |                  |             |
   | UID          | TEXT              |                  | 1\*TEXT     |
   | CONTACT      | TEXT              |                  | 1\*TEXT     |
   | DTSTART      | ISO-DATE-TIME-    | ISO-DATE-        | DATE-TIME,  |
   |              | BASIC             | COMPLETE         | DATE        |
   | DTEND        | ISO-DATE-TIME-    | ISO-DATE-        | DATE-TIME,  |
   |              | BASIC             | COMPLETE         | DATE        |
   | ORGANIZER    | URI               |                  | cal-address |
   | URL          | URI               |                  | URI         |
   | ATTENDEE     | URI               |                  | cal-address |
   | COMMENT      | TEXT              |                  | 1\*TEXT     |
   | FREEBUSY     | LIST(CAL-         |                  | LIST(PERIOD |
   |              | INTERVAL)         |                  | )           |
   | REQUEST-     | TEXT              |                  | 1\*TEXT     |
   | STATUS       |                   |                  |             |
   | IANA-        | TEXT              |                  | 1\*TEXT     |
   | REGed/X-     |                   |                  |             |
   +--------------+-------------------+------------------+-------------+

13.7.  VTIMEZONE Component (RFC 5545)

   +---------------+---------------------+------------+----------------+
   | Property      | Default Value Type  | Alt. Value | Original Value |
   |               |                     | Types      | Type           |
   +---------------+---------------------+------------+----------------+
   | TZID          | TEXT                |            | 1\*TEXT        |
   | LAST-MODIFIED | ISO-DATE-TIME-BASIC |            | DATE-TIME      |
   | TZURL         | URI                 |            | URI            |
   | IANA-REGed/X- | TEXT                |            | 1\*TEXT        |
   +---------------+---------------------+------------+----------------+

13.8.  STANDARD / DAYLIGHT Components (RFC 5545)












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   +--------------+--------------------+------------------+------------+
   | Property     | Default Value Type | Alt. Value Types | Original   |
   |              |                    |                  | Value Type |
   +--------------+--------------------+------------------+------------+
   | DTSTART      | ISO-DATE-TIME-     | ISO-DATE-        | DATE-TIME, |
   |              | BASIC              | COMPLETE         | DATE       |
   | TZOFFSETFROM | CAL-UTC-OFFSET     |                  | UTC-OFFSET |
   | TZOFFSETTO   | CAL-UTC-OFFSET     |                  | UTC-OFFSET |
   | RRULE        | RECURMAP (Section  |                  | RECUR      |
   |              | 12.2.1)            |                  |            |
   | COMMENT      | TEXT               |                  | 1\*TEXT    |
   | RDATE        | LIST( ISO-DATE-    |                  | DATE-TIME, |
   |              | TIME-BASIC / ISO-  |                  | DATE,      |
   |              | DATE-COMPLETE /    |                  | PERIOD     |
   |              | CAL-INTERVAL)      |                  |            |
   | TZNAME       | TEXT               |                  | 1\*TEXT    |
   | IANA-        | TEXT               |                  | 1\*TEXT    |
   | REGed/X-     |                    |                  |            |
   +--------------+--------------------+------------------+------------+

13.9.  VALARM Component (RFC 5545)

   +---------------+-------------+---------------------+---------------+
   | Property      | Default     | Alt. Value Types    | Original      |
   |               | Value Type  |                     | Value Type    |
   +---------------+-------------+---------------------+---------------+
   | ACTION        | TEXT        |                     | 1\*TEXT       |
   | DESCRIPTION   | TEXT        |                     | 1\*TEXT       |
   | SUMMARY       | TEXT        |                     | 1\*TEXT       |
   | TRIGGER       | DURATION    | ISO-DATE-TIME-BASIC | DURATION,     |
   |               |             |                     | DATE-TIME     |
   | DURATION      | DURATION    |                     | DURATION      |
   | REPEAT        | INTEGER-32  |                     | INTEGER       |
   | ATTACH        | URI         | BINARY              | URI, BINARY   |
   | ATTENDEE      | URI         |                     | cal-address   |
   | IANA-REGed/X- | TEXT        |                     | 1\*TEXT       |
   +---------------+-------------+---------------------+---------------+

14.  Mapping Of Parameter Value Types For Existing RFCs

   The value types in this section are described using vObject value
   type notation (see Section 5.1).

14.1.  RFC 6350







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                       +-----------+--------------+
                       | Parameter | Value Type   |
                       +-----------+--------------+
                       | LANGUAGE  | LANGUAGE-TAG |
                       | VALUE     | TEXT         |
                       | PREF      | INTEGER-64   |
                       | ALTID     | TEXT         |
                       | PID       | TEXT         |
                       | TYPE      | LIST(TEXT)   |
                       | MEDIATYPE | TEXT         |
                       | CALSCALE  | TEXT         |
                       | SORT-AS   | LIST(TEXT)   |
                       | GEO       | URI          |
                       | TZ        | TEXT         |
                       +-----------+--------------+

14.2.  RFC 5545

                     +----------------+--------------+
                     | Parameter      | Value Type   |
                     +----------------+--------------+
                     | ALTREP         | URI          |
                     | CN             | TEXT         |
                     | CUTYPE         | TEXT         |
                     | DELEGATED-FROM | URI          |
                     | DELEGATED-TO   | URI          |
                     | DIR            | URI          |
                     | ENCODING       | TEXT         |
                     | FMTTYPE        | TEXT         |
                     | FBTYPE         | TEXT         |
                     | LANGUAGE       | LANGUAGE-TAG |
                     | MEMBER         | LIST(URI)    |
                     | PARTSTAT       | TEXT         |
                     | RANGE          | TEXT         |
                     | RELATED        | TEXT         |
                     | RELTYPE        | TEXT         |
                     | ROLE           | TEXT         |
                     | RSVP           | BOOLEAN      |
                     | SENT-BY        | URI          |
                     | TZID           | TEXT         |
                     | VALUE          | TEXT         |
                     +----------------+--------------+

15.  References







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15.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
              Resource Identifier (URI): Generic Syntax", STD 66,
              RFC 3986, DOI 10.17487/RFC3986, January 2005,
              <https://www.rfc-editor.org/info/rfc3986>.

   [RFC5545]  Desruisseaux, B., Ed., "Internet Calendaring and
              Scheduling Core Object Specification (iCalendar)",
              RFC 5545, DOI 10.17487/RFC5545, September 2009,
              <https://www.rfc-editor.org/info/rfc5545>.

   [RFC5646]  Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying
              Languages", BCP 47, RFC 5646, DOI 10.17487/RFC5646,
              September 2009, <https://www.rfc-editor.org/info/rfc5646>.

   [RFC6350]  Perreault, S., "vCard Format Specification", RFC 6350,
              DOI 10.17487/RFC6350, August 2011,
              <https://www.rfc-editor.org/info/rfc6350>.

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

15.2.  Informative References

   [CALCONNECT-CALENDAR]
              The Calendaring and Scheduling Consortium, "CalConnect
              CALENDAR Technical Committee", April 2018,
              <https://www.calconnect.org/about/technical-committees/
              calendar-technical-committee>.

   [CALCONNECT-VCARD]
              The Calendaring and Scheduling Consortium, "CalConnect
              VCARD Technical Committee", April 2018,
              <http://www.calconnect.org/about/technical-committees/
              vcard-technical-committee>.




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   [I-D.daboo-valarm-extensions]
              Daboo, C., "VALARM Extensions for iCalendar", draft-daboo-
              valarm-extensions-04 (work in progress), June 2012.

   [I-D.york-vpoll]
              York, E., Daboo, C., and M. Douglass, "VPOLL: Consensus
              Scheduling Component for iCalendar", draft-york-vpoll-04
              (work in progress), February 2017.

   [IEEE.754.2008]
              Institute of Electrical and Electronics Engineers, "IEEE
              Standard 754, Standard for Binary Floating-Point
              Arithmetic", August 2008,
              <https://doi.org/10.1109/IEEESTD.2008.4610935>.

   [ISO.8601.2000]
              ISO/IEC, "ISO 8601:2000, Data elements and interchange
              formats -- Information interchange -- Representation of
              dates and times", December 2000,
              <https://www.iso.org/standard/26780.html>.

   [ISO.8601.2004]
              ISO/IEC, "ISO 8601:2004, Data elements and interchange
              formats -- Information interchange -- Representation of
              dates and times", December 2004,
              <https://www.iso.org/standard/40874.html>.

   [RFC2045]  Freed, N. and N. Borenstein, "Multipurpose Internet Mail
              Extensions (MIME) Part One: Format of Internet Message
              Bodies", RFC 2045, DOI 10.17487/RFC2045, November 1996,
              <https://www.rfc-editor.org/info/rfc2045>.

   [RFC3552]  Rescorla, E. and B. Korver, "Guidelines for Writing RFC
              Text on Security Considerations", BCP 72, RFC 3552,
              DOI 10.17487/RFC3552, July 2003,
              <https://www.rfc-editor.org/info/rfc3552>.

   [RFC3629]  Yergeau, F., "UTF-8, a transformation format of ISO
              10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
              2003, <https://www.rfc-editor.org/info/rfc3629>.

   [RFC4648]  Josefsson, S., "The Base16, Base32, and Base64 Data
              Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006,
              <https://www.rfc-editor.org/info/rfc4648>.







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   [RFC4791]  Daboo, C., Desruisseaux, B., and L. Dusseault,
              "Calendaring Extensions to WebDAV (CalDAV)", RFC 4791,
              DOI 10.17487/RFC4791, March 2007,
              <https://www.rfc-editor.org/info/rfc4791>.

   [RFC5234]  Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
              Specifications: ABNF", STD 68, RFC 5234,
              DOI 10.17487/RFC5234, January 2008,
              <https://www.rfc-editor.org/info/rfc5234>.

   [RFC5789]  Dusseault, L. and J. Snell, "PATCH Method for HTTP",
              RFC 5789, DOI 10.17487/RFC5789, March 2010,
              <https://www.rfc-editor.org/info/rfc5789>.

   [RFC6321]  Daboo, C., Douglass, M., and S. Lees, "xCal: The XML
              Format for iCalendar", RFC 6321, DOI 10.17487/RFC6321,
              August 2011, <https://www.rfc-editor.org/info/rfc6321>.

   [RFC6351]  Perreault, S., "xCard: vCard XML Representation",
              RFC 6351, DOI 10.17487/RFC6351, August 2011,
              <https://www.rfc-editor.org/info/rfc6351>.

   [RFC6352]  Daboo, C., "CardDAV: vCard Extensions to Web Distributed
              Authoring and Versioning (WebDAV)", RFC 6352,
              DOI 10.17487/RFC6352, August 2011,
              <https://www.rfc-editor.org/info/rfc6352>.

   [RFC7095]  Kewisch, P., "jCard: The JSON Format for vCard", RFC 7095,
              DOI 10.17487/RFC7095, January 2014,
              <https://www.rfc-editor.org/info/rfc7095>.

   [RFC7265]  Kewisch, P., Daboo, C., and M. Douglass, "jCal: The JSON
              Format for iCalendar", RFC 7265, DOI 10.17487/RFC7265, May
              2014, <https://www.rfc-editor.org/info/rfc7265>.

   [RFC7953]  Daboo, C. and M. Douglass, "Calendar Availability",
              RFC 7953, DOI 10.17487/RFC7953, August 2016,
              <https://www.rfc-editor.org/info/rfc7953>.

   [RFC7986]  Daboo, C., "New Properties for iCalendar", RFC 7986,
              DOI 10.17487/RFC7986, October 2016,
              <https://www.rfc-editor.org/info/rfc7986>.

   [RFC8259]  Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
              Interchange Format", STD 90, RFC 8259,
              DOI 10.17487/RFC8259, December 2017,
              <https://www.rfc-editor.org/info/rfc8259>.




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   [vCard21]  Internet Mail Consortium, "vCard - The Electronic Business
              Card Version 2.1", 09 1996.

   [VPATCH]   Daboo, C. and K. Murchison, "The iCalendar VPATCH
              Component (draft)", 10 2016.

Appendix A.  Normalization Examples for vFormat

   Original:

   BEGIN:VOBJECT
   PROPERTY1:10
   PROPERTY2:20
   END:VOBJECT

   Normalized:

   BEGIN:VOBJECT
   PROPERTY1:10
   PROPERTY2:20
   END:VOBJECT

A.1.  vCard

   Original:

BEGIN:VCARD
VERSION:4.0
KIND:individual
FN:Martin Van Buren
N:Van Buren;Martin;;;Hon.
TEL;VALUE=uri;PREF=1;TYPE="voice";TYPE="home":tel:+1-888-888-8888;ext=8888
END:VCARD

   Normalized:

   BEGIN:VCARD
   VERSION:4.0
   KIND:individual
   FN:Martin Van Buren
   N:Van Buren;Martin;;;Hon.
   TEL;VALUE=uri;PREF=1;TYPE="voice","home":tel:+1-888-888-8888;ext=8888
   END:VCARD








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Appendix B.  Acknowledgements

   The authors wish to thank their families and the following parties
   who helped this materialize and for their support of a better and
   vObject-enabled world:

   o  The CalConnect TC-VCARD and TC-CALENDAR committees

   o  Cyrus Daboo

   o  Marten Gajda

   o  The CalConnect Technical Coordination Committee ("TCC")

   o  Members and the Board of Directors of CalConnect

Authors' Addresses

   Ronald Henry Tse
   Ribose
   Suite 1111, 1 Pedder Street
   Central
   Hong Kong

   Email: ronald.tse@ribose.com
   URI:   https://www.ribose.com


   Peter Kwan Yu Tam
   Ribose
   Suite 1111, 1 Pedder Street
   Central
   Hong Kong

   Email: peter.tam@ribose.com
   URI:   https://www.ribose.com


   Kenneth Murchison
   FastMail Pty Ltd
   Level 2, 114 William Street
   Melbourne, VIC  3000
   Australia

   Email: murch@fastmailteam.com






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   Mike Douglass
   Spherical Cow Group
   226 3rd Street
   Troy, NY  12180
   United States of America

   Email: mdouglass@sphericalcowgroup.com
   URI:   http://sphericalcowgroup.com











































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