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Versions: 00 01 02 03 04 05 06 07 08 09 10 11 RFC 6321

Network Working Group                                           C. Daboo
Internet-Draft                                               Apple, Inc.
Intended status: Standards Track                             M. Douglass
Expires: December 6, 2009                                            RPI
                                                                 S. Lees
                                                               Microsoft
                                                            June 4, 2009


                      iCalendar XML Representation
                 draft-daboo-et-al-icalendar-in-xml-00

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   This Internet-Draft will expire on December 6, 2009.

Copyright Notice

   Copyright (c) 2009 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
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   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.






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Abstract

   This specification defines a format for representing iCalendar data
   in XML.

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Conventions Used in This Document  . . . . . . . . . . . . . .  3
   3.  Converting from iCalendar to XML . . . . . . . . . . . . . . .  4
     3.1.  Pre-processing . . . . . . . . . . . . . . . . . . . . . .  4
     3.2.  iCalendar stream (2445bis section 3.4) . . . . . . . . . .  4
     3.3.  Components (2445bis section 3.6) . . . . . . . . . . . . .  6
     3.4.  Properties (2445bis section 3.5) . . . . . . . . . . . . .  6
       3.4.1.  Special Cases for Properties . . . . . . . . . . . . .  8
         3.4.1.1.  Multi-valued Properties  . . . . . . . . . . . . .  8
         3.4.1.2.  GEO Property . . . . . . . . . . . . . . . . . . .  9
         3.4.1.3.  REQUEST-STATUS Property  . . . . . . . . . . . . .  9
     3.5.  Parameters (2445bis section 3.4) . . . . . . . . . . . . .  9
       3.5.1.  VALUE parameter  . . . . . . . . . . . . . . . . . . . 10
     3.6.  Values (2445bis section 3.3) . . . . . . . . . . . . . . . 11
       3.6.1.  Binary (2445bis section 4.3.1) . . . . . . . . . . . . 11
       3.6.2.  Boolean  (2445bis section 4.3.2) . . . . . . . . . . . 11
       3.6.3.  Calendar User Address (2445bis section 4.3.3)  . . . . 11
       3.6.4.  Date (2445bis section 4.3.4) . . . . . . . . . . . . . 11
       3.6.5.  Date-Time (2445bis section 4.3.5)  . . . . . . . . . . 12
       3.6.6.  Duration (2445bis section 4.3.6) . . . . . . . . . . . 12
       3.6.7.  Float (2445bis section 4.3.7)  . . . . . . . . . . . . 12
       3.6.8.  Integer (2445bis section 4.3.8)  . . . . . . . . . . . 12
       3.6.9.  Period of Time (2445bis section 4.3.9) . . . . . . . . 13
       3.6.10. Recurrence Rule (2445bis section 4.3.10) . . . . . . . 13
       3.6.11. Text (2445bis section 4.3.11)  . . . . . . . . . . . . 13
       3.6.12. Time (2445bis section 4.3.12)  . . . . . . . . . . . . 13
       3.6.13. URI (2445bis section 4.3.13) . . . . . . . . . . . . . 13
       3.6.14. UTC Offset (2445bis section 4.3.14)  . . . . . . . . . 13
     3.7.  Extensions . . . . . . . . . . . . . . . . . . . . . . . . 14
   4.  Converting from XML into iCalendar . . . . . . . . . . . . . . 14
   5.  Security Considerations  . . . . . . . . . . . . . . . . . . . 14
   6.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 14
     6.1.  Namespace Registration . . . . . . . . . . . . . . . . . . 14
     6.2.  Media Type . . . . . . . . . . . . . . . . . . . . . . . . 15
   7.  Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 16
   8.  Normative References . . . . . . . . . . . . . . . . . . . . . 16
   Appendix A.  Relax NG Schema . . . . . . . . . . . . . . . . . . . 16
   Appendix B.  XML Stylesheet for conversion to iCalendar  . . . . . 40
   Appendix C.  Example . . . . . . . . . . . . . . . . . . . . . . . 40
     C.1.  iCalendar Data . . . . . . . . . . . . . . . . . . . . . . 40
     C.2.  XML Data . . . . . . . . . . . . . . . . . . . . . . . . . 41



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1.  Introduction

   The iCalendar data format [I-D.ietf-calsify-rfc2445bis] is a widely
   deployed interchange format for calendaring and scheduling data.
   While many applications and services consume and generate calendar
   data, iCalendar is a specialized format that requires its own parser/
   generator.  In contrast, XML-based formats are widely used for
   interoperability between applications, and the many tools that
   generate, parse, and manipulate XML make it easier to work with than
   iCalendar.

   The purpose of this specification is to define an XML format that
   allows iCalendar data to be converted to XML, and then back to
   iCalendar, without losing any semantic meaning in the data.  Anyone
   creating XML calendar data according to this specification will know
   that their data can be converted to a valid iCalendar representation
   as well.

   Several key design decisions have been made:

      Round-tripping: i.e., converting an iCalendar instance to XML and
      back will give the same result as the starting point.

      Make the conversion process as simple as possible.

      Make it easy to work with the XML without needing to re-parse it.
      It is worth explaining the rationale behind this decision.  One
      result is that this specification breaks up date/time values from
      iCalendar into separate year, month, day, hour, minute, and second
      elements.  By separating the values into different elements, it
      becomes much easier to transform or query over the resulting XML.
      For instance, given a set of xCal elements representing events, it
      is easy to find the events that start at a particular time or in a
      particular year, month, or day.  Given a date / time value in the
      xCal format described here, it would be easy to transform it to
      HTML while removing unneeded sub-elements; no additional parsing
      is needed.

      Preserve the semantics of the iCalendar data.  This decision is
      important: the semantics of iCalendar is preserved in the XML so a
      full understanding of iCalendar is required in order to actually
      use the data, whether it be in the iCalendar or XML formats.

2.  Conventions Used in This Document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].



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   When XML element types in the namespace
   "urn:ietf:params:xml:ns:icalendar" are referenced in this document
   outside of the context of an XML fragment, the string "ICAL:" will be
   prefixed to the element types.

   Some examples in this document contain "partial" XML documents used
   for illustrative purposes.  In these examples, three periods "..."
   are used to indicate a portion of the document that has been removed
   for compactness.

3.  Converting from iCalendar to XML

   This section describes how iCalendar data is converted to XML using a
   simple, predictable mapping between the iCalendar data model and XML
   elements.

3.1.  Pre-processing

   iCalendar data uses a line folding mechanism to limit lines of data
   to a maximum line length (typically 72 characters) to ensure maximum
   likelihood of preserving data integrity as it is transported via
   various means (e.g., email) - see Section 3.1 of
   [I-D.ietf-calsify-rfc2445bis].

   Prior to converting iCalendar data into XML all folded lines MUST be
   unfolded.

   iCalendar data uses an "escape" character sequence for text values
   and parameter values.  When such text elements are converted into XML
   the escaping MUST be removed.

   iCalendar uses a base64 encoding for binary data.  The base64
   encoding MUST remain when converted to XML.

3.2.  iCalendar stream (2445bis section 3.4)

   iCalendar has a well defined object model for its data that makes
   mapping to XML a simple process of following a set of rules for
   mapping the various object model types into XML elements.

   At the top-level of the iCalendar object model is an "iCalendar
   stream".  This object encompasses multiple "iCalendar objects".  In
   XML, the entire stream is contained in the root ICAL:icalendar XML
   element.

   Example:





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   <?xml version="1.0" encoding="utf-8"?>
   <icalendar xmlns="urn:ietf:params:xml:ns:icalendar">
   ...
   </icalendar>

   An iCalendar stream can contain one or more iCalendar objects.  Each
   iCalendar object, delimited by BEGIN:VCALENDAR and END:VCALENDAR, is
   enclosed by the ICAL:vcalendar XML element.

   Example:

   <?xml version="1.0" encoding="utf-8"?>
   <icalendar xmlns="urn:ietf:params:xml:ns:icalendar">
     <vcalendar>
     ...
     </vcalendar>
   </icalendar>

   iCalendar objects are comprised of a set of "components",
   "properties", "parameters" and "values".  A "component" can contain
   other "components" or "properties".  A "property" has a value and
   optionally a set of "parameters".

   In XML, "components" are contained within an ICAL:components XML
   element.  With that element, another ICAL:components element could
   appear (representing components nested within components) or the
   ICAL:properties XML element could appear.  ICAL:properties is used to
   encapsulate iCalendar properties.

   Each iCalendar property will be mapped to its own XML element as
   described below.  Within each of these elements there is an optional
   ICAL:parameters XML element used to encapsulate any iCalendar
   parameters.  Additionally there will be one or more XML elements
   representing the value of the iCalendar property.

   Example:

   <?xml version="1.0" encoding="utf-8"?>
   <icalendar xmlns="urn:ietf:params:xml:ns:icalendar">
     <vcalendar>
       <properties>
       ...
       </properties>
       <components>
       ...
       </components>
     </vcalendar>
   </icalendar>



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         +------------------+----------------+------------------+
         | Item             | XML element    | XML Definition   |
         +------------------+----------------+------------------+
         | iCalendar Stream | ICAL:icalendar | Appendix A # 3.4 |
         | VCALENDAR        | ICAL:vcalendar | Appendix A # 3.6 |
         +------------------+----------------+------------------+

3.3.  Components (2445bis section 3.6)

   Each calendar component in the VCALENDAR object, delimited by BEGIN
   and END, will be converted to an enclosing XML element with the same
   name, but in lowercase:

            +-----------+----------------+--------------------+
            | Component | XML element    | XML Definition     |
            +-----------+----------------+--------------------+
            | VEVENT    | ICAL:vevent    | Appendix A # 3.6.1 |
            | VTODO     | ICAL:vtodo     | Appendix A # 3.6.2 |
            | VJOURNAL  | ICAL:vjournal  | Appendix A # 3.6.3 |
            | VFREEBUSY | ICAL:vfreebusy | Appendix A # 3.6.4 |
            | VTIMEZONE | ICAL:vtimezone | Appendix A # 3.6.5 |
            | STANDARD  | ICAL:standard  | Appendix A # 3.6.5 |
            | DAYLIGHT  | ICAL:daylight  | Appendix A # 3.6.5 |
            | VALARM    | ICAL:valarm    | Appendix A # 3.6.6 |
            +-----------+----------------+--------------------+

3.4.  Properties (2445bis section 3.5)

   iCalendar properties , whether they apply to the VCALENDAR object or
   to the components, are handled in a consistent way.

   iCalendar properties are enclosed in the XML element ICAL:properties.

   Each invidivual iCalendar property is represented in XML by an
   element of the same name as the iCalendar property, but in lowercase.
   For example, the CALSCALE property is represented in XML by the ICAL:
   calscale element.

   Example:












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   <?xml version="1.0" encoding="utf-8"?>
   <icalendar xmlns="urn:ietf:params:xml:ns:icalendar">
     <vcalendar>
       <properties>
         <calscale>...</calscale>
         <version>...</version>
         <prodid>...</prodid>
       </properties>
       <components>
       ...
       </components>
     </vcalendar>
   </icalendar>

   Each property can contain an ICAL:parameters XML element
   encapsulating any iCalendar parameters associated with the iCalendar
   property.

   Each property will contain one or more "value" XML elements as
   described below representing the value of the iCalendar property.

   +------------------+-----------------------+-----------------------+
   | Property         | XML element           | XML Definition        |
   +------------------+-----------------------+-----------------------+
   | CALSCALE         | ICAL:calscale         | Appendix A # 3.7.1    |
   | METHOD           | ICAL:method           | Appendix A # 3.7.2    |
   | PRODID           | ICAL:prodid           | Appendix A # 3.7.3    |
   | VERSION          | ICAL:version          | Appendix A # 3.7.4    |
   | ATTACH           | ICAL:attach           | Appendix A # 3.8.1.1  |
   | CATEGORIES       | ICAL:categories       | Appendix A # 3.8.1.2  |
   | CLASS            | ICAL:class            | Appendix A # 3.8.1.3  |
   | COMMENT          | ICAL:comment          | Appendix A # 3.8.1.4  |
   | DESCRIPTION      | ICAL:description      | Appendix A # 3.8.1.5  |
   | GEO              | ICAL:geo              | Appendix A # 3.8.1.6  |
   | LOCATION         | ICAL:location         | Appendix A # 3.8.1.7  |
   | PERCENT-COMPLETE | ICAL:percent-complete | Appendix A # 3.8.1.8  |
   | PRIORITY         | ICAL:priority         | Appendix A # 3.8.1.9  |
   | RESOURCES        | ICAL:resources        | Appendix A # 3.8.1.10 |
   | STATUS           | ICAL:status           | Appendix A # 3.8.1.11 |
   | SUMMARY          | ICAL:summary          | Appendix A # 3.8.1.12 |
   | COMPLETED        | ICAL:completed        | Appendix A # 3.8.2.1  |
   | DTEND            | ICAL:dtend            | Appendix A # 3.8.2.2  |
   | DUE              | ICAL:due              | Appendix A # 3.8.2.3  |
   | DTSTART          | ICAL:dtstart          | Appendix A # 3.8.2.4  |
   | DURATION         | ICAL:duration         | Appendix A # 3.8.2.5  |
   | FREEBUSY         | ICAL:freebusy         | Appendix A # 3.8.2.6  |
   | TRANSP           | ICAL:transp           | Appendix A # 3.8.2.7  |
   | TZID             | ICAL:tzid             | Appendix A # 3.8.3.1  |



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   | TZNAME           | ICAL:tzname           | Appendix A # 3.8.3.2  |
   | TZOFFSETFROM     | ICAL:tzoffsetfrom     | Appendix A # 3.8.3.3  |
   | TZOFFSETTO       | ICAL:tzoffsetto       | Appendix A # 3.8.3.4  |
   | TZURL            | ICAL:tzurl            | Appendix A # 3.8.3.5  |
   | ATTENDEE         | ICAL:attendee         | Appendix A # 3.8.4.1  |
   | CONTACT          | ICAL:contact          | Appendix A # 3.8.4.2  |
   | ORGANIZER        | ICAL:organizer        | Appendix A # 3.8.4.3  |
   | RECURRENCE-ID    | ICAL:recurrence-id    | Appendix A # 3.8.4.4  |
   | RELATED-TO       | ICAL:related-to       | Appendix A # 3.8.4.5  |
   | URL              | ICAL:url              | Appendix A # 3.8.4.6  |
   | UID              | ICAL:uid              | Appendix A # 3.8.4.7  |
   | EXDATE           | ICAL:exdate           | Appendix A # 3.8.5.1  |
   | RDATE            | ICAL:rdate            | Appendix A # 3.8.5.2  |
   | RRULE            | ICAL:rrule            | Appendix A # 3.8.5.3  |
   | ACTION           | ICAL:action           | Appendix A # 3.8.6.1  |
   | REPEAT           | ICAL:repeat           | Appendix A # 3.8.6.2  |
   | TRIGGER          | ICAL:trigger          | Appendix A # 3.8.6.3  |
   | CREATED          | ICAL:created          | Appendix A # 3.8.7.1  |
   | DTSTAMP          | ICAL:dtstamp          | Appendix A # 3.8.7.2  |
   | LAST-MODIFIED    | ICAL:last-modified    | Appendix A # 3.8.7.3  |
   | SEQUENCE         | ICAL:sequence         | Appendix A # 3.8.7.4  |
   | REQUEST-STATUS   | ICAL:request-status   | Appendix A # 3.8.8.3  |
   +------------------+-----------------------+-----------------------+

3.4.1.  Special Cases for Properties

   Some properties in iCalendar can contain "structured" value data.
   This includes lists of "standard" value types, as well as values with
   specific "fields".  In XML, these "structured" values are represented
   as separate XML elements in various ways for ease of processing using
   standard XML tools.

3.4.1.1.  Multi-valued Properties

   The following iCalendar properties can have values that consist of a
   list of "standard" iCalendar values separated by a specific
   delimiter.  In XML these properties are represented by an XML element
   that contains multiple "value" elements (Section 3.6).

         +------------+-----------------+-----------------------+
         | Property   | XML element     | XML Definition        |
         +------------+-----------------+-----------------------+
         | CATEGORIES | ICAL:categories | Appendix A # 3.8.1.2  |
         | RESOURCES  | ICAL:resources  | Appendix A # 3.8.1.10 |
         | FREEBUSY   | ICAL:freebusy   | Appendix A # 3.8.2.6  |
         | EXDATE     | ICAL:exdate     | Appendix A # 3.8.5.1  |
         | RDATE      | ICAL:rdate      | Appendix A # 3.8.5.2  |
         +------------+-----------------+-----------------------+



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3.4.1.2.  GEO Property

   In iCalendar, the GEO property value is defined as a semi-colon
   separated list of two FLOAT values, the first representing latitude
   and the second longitude.

   In XML, the value for the ICAL:geo element is represented by an ICAL:
   value element containing an ICAL:latitude element and an ICAL:
   longitude element, each of which contain text values representing the
   FLOAT values.  See Appendix A # 3.8.1.6.

3.4.1.3.  REQUEST-STATUS Property

   In Icalendar, the REQUEST-STATUS property value is defined as a semi-
   colon separated list of two or three TEXT values.  The first
   represents a code, the second a description, and the third (optional)
   additional data.

   In XML, the value for the ICAL:request-status element is represented
   by an ICAL:value element containing an ICAL:code element, and iCAL:
   description element, and optionally and ICAL:data element, each of
   which contain the corresponding TEXT values.  See Appendix A #
   3.8.8.3.

3.5.  Parameters (2445bis section 3.4)

   iCalendar parameters are enclosed in the XML element ICAL:parameters
   which optionally occurs once in each property XML element.

   Each invidivual iCalendar parameter is represented in XML by an
   element of the same name as the iCalendar parameter, but in
   lowercase.  For example, the PARTSTAT parameter is represented in XML
   by the ICAL:partstat element.

   Example:
















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   <?xml version="1.0" encoding="utf-8"?>
   <icalendar xmlns="urn:ietf:params:xml:ns:icalendar">
     <vcalendar>
       ...
       <components>
       ...
         <attendee>
           <parameters>
             <partstat>NEEDS-ACTION</partstat>
           </parameters>
           ...
       </components>
     </vcalendar>
   </icalendar>

   Each parameter contains either text, or one or more child XML
   elements representing iCalendar value types.

      +----------------+---------------------+---------------------+
      | Parameter      | XML element         | XML Definition      |
      +----------------+---------------------+---------------------+
      | ALTREP         | ICAL:altrep         | Appendix A # 3.2.1  |
      | CN             | ICAL:cn             | Appendix A # 3.2.2  |
      | CUTYPE         | ICAL:cutype         | Appendix A # 3.2.3  |
      | DELEGATED-FROM | ICAL:delegated-from | Appendix A # 3.2.4  |
      | DELEGATED-TO   | ICAL:delegated-to   | Appendix A # 3.2.5  |
      | DIR            | ICAL:dir            | Appendix A # 3.2.6  |
      | ENCODING       | ICAL:encoding       | Appendix A # 3.2.7  |
      | FMTTYPE        | ICAL:fmttype        | Appendix A # 3.2.8  |
      | FBTYPE         | ICAL:fbtype         | Appendix A # 3.2.9  |
      | LANGUAGE       | ICAL:language       | Appendix A # 3.2.10 |
      | MEMBER         | ICAL:member         | Appendix A # 3.2.11 |
      | PARTSTAT       | ICAL:partstat       | Appendix A # 3.2.12 |
      | RANGE          | ICAL:range          | Appendix A # 3.2.13 |
      | RELATED        | ICAL:related        | Appendix A # 3.2.14 |
      | RELTYPE        | ICAL:reltype        | Appendix A # 3.2.15 |
      | ROLE           | ICAL:role           | Appendix A # 3.2.16 |
      | RSVP           | ICAL:rsvp           | Appendix A # 3.2.17 |
      | SENT-BY        | ICAL:sent-by        | Appendix A # 3.2.18 |
      | TZID           | ICAL:tzid           | Appendix A # 3.2.19 |
      +----------------+---------------------+---------------------+

3.5.1.  VALUE parameter

   iCalendar defines a VALUE parameter (Section 3.2.20 of
   [I-D.ietf-calsify-rfc2445bis].  This parameter is not mapped to an
   XML element.  Instead, the value type is handled by having different
   XML elements for each value, and these appear inside of ICAL:property



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   elements.  Thus, when converting from iCalendar to XML, any VALUE
   parameters are skipped.  When converting from XML into iCalendar, the
   appropriate VALUE parameter MUST be included in the iCalendar
   property if the value type is not the default value type for that
   property.

3.6.  Values (2445bis section 3.3)

   iCalendar value types are mapped into XML elements with a matching
   name in all lowercase.  In some cases, iCalendar defines "structured"
   values and these are mapped into separate child elements in each
   value element, as described by the simple DTD definitions below.

   Some properties allow for multiple values and these are represented
   by separate matching value XML elements.

3.6.1.  Binary (2445bis section 4.3.1)

   Description:  iCalendar BINARY property values are represented by the
      ICAL:binary XML element.  The content of the element is base64
      encoded data.  Whitespace MAY be inserted into the data at any
      point to "wrap" the data to reasonable line lengths.  When
      converting back to iCalendar the whitespace MUST first be removed.

   XML Definition:  Appendix A # 3.3.1

3.6.2.  Boolean  (2445bis section 4.3.2)

   Description:  iCalendar BOOLEAN property values are represented by
      the ICAL:boolean XML element.  The content of the element is text
      containing either of "TRUE" or "FALSE".

   XML Definition:  Appendix A # 3.3.2

3.6.3.  Calendar User Address (2445bis section 4.3.3)

   Description:  iCalendar CAL-ADDRESS property values are represented
      by the ICAL:cal-address XML element.  The content of the element
      is a URI.

   XML Definition:  Appendix A # 3.3.3

3.6.4.  Date (2445bis section 4.3.4)








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   Description:  iCalendar DATE property values are represented by the
      ICAL:date XML element.  The content of the element is three child
      elements representing the year, month and day values in the date.

   XML Definition:  Appendix A # 3.3.4

3.6.5.  Date-Time (2445bis section 4.3.5)

   Description:  iCalendar DATE-TIME property values are represented by
      the ICAL:date-time XML element.  The content of the element is six
      child elements representing the year, month, day, hour, minute and
      second values in the date-time.  In addition, an XML attribute is
      used to indicate whether the date-time value represents a UTC
      based date-time (represented by a trailing "Z" in the iCalendar
      value).

   XML Definition:  Appendix A # 3.3.5

3.6.6.  Duration (2445bis section 4.3.6)

   Description:  iCalendar DURATION property values are represented by
      the ICAL:duration XML element.  The content of the element is
      various child elements representing the possible combinations of
      week, day, hour, minute and second values.  In addition, an XML
      attribute is used to indicate whether the duration value
      represents a positive or negative offset.

   XML Definition:  Appendix A # 3.3.6

3.6.7.  Float (2445bis section 4.3.7)

   Description:  iCalendar FLOAT property values are represented by the
      ICAL:float XML element.  The content of the element is a text
      representation of a floating point number.

   XML Definition:  Appendix A # 3.3.7

3.6.8.  Integer (2445bis section 4.3.8)

   Description:  iCalendar INTEGER property values are represented by
      the ICAL:integer XML element.  The content of the element is a
      text representation of an integer number.

   XML Definition:  Appendix A # 3.3.8







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3.6.9.  Period of Time (2445bis section 4.3.9)

   Description:  iCalendar PERIOD property values are represented by the
      ICAL:period XML element.  The content of the element is two child
      elements representing the start date-time and end date-time or
      positive duration.

   XML Definition:  Appendix A # 3.3.9

3.6.10.  Recurrence Rule (2445bis section 4.3.10)

   Description:  iCalendar RECUR property values are represented by the
      ICAL:recur XML element.  The content of the element is child
      elements representing the various components of a recurrence rule.

   XML Definition:  Appendix A # 3.3.10

3.6.11.  Text (2445bis section 4.3.11)

   Description:  iCalendar TEXT property values are represented by the
      ICAL:text XML element.  The content of the element is simple text.

   XML Definition:  Appendix A # 3.3.11

3.6.12.  Time (2445bis section 4.3.12)

   Description:  iCalendar TIME property values are represented by the
      ICAL:time XML element.  The content of the element is three child
      elements representing the hour, minute and second values in the
      time.  In addition, an XML attribute is used to indicate whether
      the time value represents a UTC based time (represented by a
      trailing "Z" in the iCalendar value).

   XML Definition:  Appendix A # 3.3.12

3.6.13.  URI (2445bis section 4.3.13)

   Description:  iCalendar URI property values are represented by the
      ICAL:uri XML element.  The content of the element is a URI.

   XML Definition:  Appendix A # 3.3.13

3.6.14.  UTC Offset (2445bis section 4.3.14)








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   Description:  iCalendar UTC-OFFSET property values are represented by
      the ICAL:utc-offset XML element.  The content of the element is
      two or three child elements representing the hour, minute and
      (optional) second values in the UTC offset.  In addition, an XML
      attribute is used to indicate whether the offset value represents
      a positive or negative offset.

   XML Definition:  Appendix A # 3.3.14

3.7.  Extensions

   iCalendar extension properties and parameters (ones with an "X-"
   prefix in their name) are handled in the same way as other properties
   and parameters: the property or parameter is represented by an XML
   element with the same name, but in lowercase. e.g., the "X-FOO"
   property in iCalendar turns into the ICAL:x-foo element in XML.

4.  Converting from XML into iCalendar

   When converting from XML back to iCalendar, any elements in the XML
   that are not in the "urn:ietf:params:xml:ns:icalendar" namespace MUST
   be ignored.

   When converting component, property and parameter values, the names
   SHOULD be converted to uppercase.  Although iCalendar names are case
   insensitive, common practice is to keep them all uppercase following
   the actual definitions in [I-D.ietf-calsify-rfc2445bis].

   Backslash escaping and line folding MUST be applied to the resulting
   iCalendar data as required by [I-D.ietf-calsify-rfc2445bis].

5.  Security Considerations

   This extension does not introduce any new security concerns than
   those already described in iCalendar.

6.  IANA Considerations

   This document uses one new URN to identify a new XML namespace, and
   one new media type.  The URN conforms to a registry mechanism
   described in [RFC3688].

6.1.  Namespace Registration

   Registration request for the iCalendar namespace:

   URI: urn:ietf:params:xml:ns:icalendar




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   Registrant Contact: See the "Authors' Addresses" section of this
   document.

   XML: None.  Namespace URIs do not represent an XML specification.

6.2.  Media Type

   This section defines the MIME media type for use with iCalendar in
   XML data.

   To:  ietf-types@iana.org

   Subject:  Registration of media type application/xml+calendar

   Type name:  application

   Subtype name:  xml+calendar

   Required parameters:  none

   Optional parameters:  charset, method, component and optinfo as
      defined for the text/calendar media type

   Encoding considerations:  iCalendar data is typically UTF-8 and thus
      the XML representation will follow that.  As a result, for 7-bit
      transports, data in UTF-8 MUST be encoded in quoted-printable or
      base64.

   Security considerations:  See Section 5.

   Interoperability considerations:  This media type provides an
      alternative syntax to iCalendar data based on XML.

   Published specification:  This specification.

   Applications which use this media type:  Applications that currently
      make use of the text/calendar media type can use this as an
      alternative.

   Additional information:

      Magic number(s):  None

      File extension(s):  XML data should use "xml" as the file
         extension.






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      Macintosh file type code(s):  None specified.

   Person & email address to contact for further information:  See the
      "Author's Address" section of this document.

   Intended usage:  COMMON

   Restrictions on usage:  There are no restrictions on where this media
      type can be used.

   Author:  See the "Author's Address" section of this document.

   Change controller:  IETF

7.  Acknowledgments

   This specification originated from the work of the XML technical
   committee of the Calendaring and Scheduling Consortium.

8.  Normative References

   [I-D.ietf-calsify-rfc2445bis]  Desruisseaux, B., "Internet
                                  Calendaring and Scheduling Core Object
                                  Specification (iCalendar)",
                                  draft-ietf-calsify-rfc2445bis-10 (work
                                  in progress), April 2009.

   [RFC2119]                      Bradner, S., "Key words for use in
                                  RFCs to Indicate Requirement Levels",
                                  BCP 14, RFC 2119, March 1997.

   [RFC3688]                      Mealling, M., "The IETF XML Registry",
                                  BCP 81, RFC 3688, January 2004.

Appendix A.  Relax NG Schema

   Below is a Relax NG schema for iCalendar in XML.  This schema uses
   the compact notation of Relax NG.  The numeric section numbers given
   in the comments refer to section in [I-D.ietf-calsify-rfc2445bis].
   The ordering of elements follows the section ordering of
   [I-D.ietf-calsify-rfc2445bis].

   The Relax NG compact notation "?" operator is used to indicate an
   unordered list of items.  However, that operator, as defined, allows
   "mixing" each element that it operates on at any depth within the
   other elements, rather than just allowing "mixing" of siblings only.
   As a result, the schema provided allows certain constructs that are
   not allowed in iCalendar.  Given that there is no sibling-only



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   unordered list operator in RelaxNG, this is the best representation
   that can be given.

   # Relax NG Schema for iCalendar in XML

   default namespace = "urn:ietf:params:xml:ns:icalendar"

   # 3.2 Property Parameters

   # 3.2.1 Alternate Text Representation

   altrepparam = element altrep { value-uri }

   # 3.2.2 Common Name

   cnparam = element cn { text }

   # 3.2.3 Calendar User Type

   cutypeparam = element cutype {
       "INDIVIDUAL" |
       "GROUP" |
       "RESOURCE" |
       "ROOM" |
       "UNKNOWN"
   }

   # 3.2.4 Delegators

   delfromparam = element delegated-from { value-cal-address+ }

   # 3.2.5 Delegatees

   deltoparam = element delegated-to { value-cal-address+ }

   # 3.2.6 Directory Entry Reference

   dirparam = element dir { value-uri }

   # 3.2.7 Inline Encoding

   encodingparam = element encoding {
       "8BIT" |
       "BASE64"
   }


   # 3.2.8 Format Type



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   fmttypeparam = element fmttype { text }

   # 3.2.9 Free/Busy Time Type

   fbtypeparam = element fbtype {
       "FREE" |
       "BUSY" |
       "BUSY-UNAVAILABLE" |
       "BUSY-TENTATIVE"
   }

   # 3.2.10 Language

   languageparam = element language { text }

   # 3.2.11 Group or List Membership

   memberparam = element member { value-cal-address+ }

   # 3.2.12 Participation Status

   partstatparam = element partstat {
       type-partstat-event |
       type-partstat-todo |
       type-partstat-jour
   }

   type-partstat-event = (
       "NEEDS-ACTION" |
       "ACCEPTED" |
       "DECLINED" |
       "TENTATIVE" |
       "DELEGATED"
   )

   type-partstat-todo = (
       "NEEDS-ACTION" |
       "ACCEPTED" |
       "DECLINED" |
       "TENTATIVE" |
       "DELEGATED" |
       "COMPLETED" |
       "IN-PROCESS"
   )

   type-partstat-jour = (
       "NEEDS-ACTION" |
       "ACCEPTED" |



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       "DECLINED"
   )

   # 3.2.13 Recurrence Identifier Range

   rangeparam = element range {
       "THISANDFUTURE"
   }

   # 3.2.14 Alarm Trigger Relationship

   trigrelparam = element related {
       "START" |
       "END"
   }

   # 3.2.15 Relationship Type

   reltypeparam = element reltype {
       "PARENT" |
       "CHILD" |
       "SIBLING"
   }

   # 3.2.16 Participation Role

   roleparam = element role {
       "CHAIR" |
       "REQ-PARTICIPANT" |
       "OPT-PARTICIPANT" |
       "NON-PARTICIPANT"
   }

   # 3.2.17 RSVP Expectation

   rsvpparam = element rsvp {
       "TRUE" |
       "FALSE"
   }

   # 3.2.18 Sent By

   sentbyparam = element sent-by { value-cal-address }

   # 3.2.19 Time Zone Identifier

   tzidparam = element tzid { text }




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   # 3.3 Property Value Data Types

   # 3.3.1 BINARY

   value-binary =  element binary { text }

   # 3.3.2 BOOLEAN

   value-boolean = element boolean {
       ("TRUE" | "FALSE")
   }

   # 3.3.3 CAL-ADDRESS

   value-cal-address = element cal-address { text }

   # 3.3.4 DATE

   value-date = element date {
       element year  { text },
       element month { text },
       element day   { text }
   }

   # 3.3.5 DATE-TIME

   value-date-time = element date-time {
       attribute utc  { "yes" | "no" },
       element year   { text },
       element month  { text },
       element day    { text },
       element hour   { text },
       element minute { text },
       element second { text }
   }

   # 3.3.6 DURATION

   value-duration = element duration {
       attribute sign { "+" | "-" },
       (
           (
               element day    { text },
               element hour   { text }?,
               element minute { text }?,
               element second { text }?
           ) |
           (



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               element hour   { text },
               element minute { text }?,
               element second { text }?
           ) |
           (
               element minute { text },
               element second { text }?
           ) |
           (
               element second { text }
           ) |
           element week { text }
       )
   }

   # 3.3.7 FLOAT

   value-float = element float { text }

   # 3.3.8 INTEGER

   value-integer = element integer { text }

   # 3.3.9 PERIOD

   value-period = element period {
       value-date-time,
       (
           value-date-time |
           value-duration
       )
   }

   # 3.3.10 RECUR

   value-recur = element recur {
       type-freq,
       (type-until | type-count)?,
       element interval  { text }?,
       element bysecond  { text }*,
       element byminute  { text }*,
       element byhour    { text }*,
       type-byday*,
       type-bymonthday*,
       type-byyearday*,
       type-byweekno*,
       element bymonth   { text }*,
       type-bysetpos*,



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       element wkst { type-weekday }?
   }

   type-freq = element freq {
       "SECONDLY" |
       "MINUTELY" |
       "HOURLY"   |
       "DAILY"    |
       "WEEKLY"   |
       "MONTHLY"  |
       "YEARLY"
   }

   type-until = element until {
       type-date |
       type-date-time
   }

   type-count = element count { text }

   type-weekday = (
       "SU" |
       "MO" |
       "TU" |
       "WE" |
       "TH" |
       "FR" |
       "SA"
   )

   type-byday = element byday {
       element ordwk {
           text
       }?,
       element weekday { type-weekday }
   }

   type-bymonthday = element bymonthday {
       text
   }

   type-byyearday = element byyearday {
       text
   }

   type-byweekno = element byweekno {
       text
   }



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   type-bysetpos = element bysetpos {
       text
   }

   # 3.3.11 TEXT

   value-text = element text { text }

   # 3.3.12 TIME

   value-time = element time {
       attribute utc  { "yes" | "no" },
       element hour   { text },
       element minute { text },
       element second { text }
   }

   # 3.3.13 URI

   value-uri = element uri { text }

   # 3.3.14 UTC-OFFSET

   value-utc-offset = element utc-offset {
       attribute sign  { "+" | "-" },
       element hour   { text },
       element minute { text },
       element second { text }?
   }


   # 3.4 iCalendar Stream

   start = element icalendar { vcalendar+ }

   # 3.6 Calendar Components

   vcalendar = element vcalendar {
       type-calprops,
       type-component
   }

   type-calprops = element properties {
       property-prodid &
       property-version &
       property-calscale? &
       property-method?
   }



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   type-component = element components {
       (
           component-vevent |
           component-vtodo |
           component-vjournal |
           component-vfreebusy |
           component-vtimezone
       )*
   }

   # 3.6.1 Event Component

   component-vevent = element vevent {
       type-eventprop,
       element components {
           component-valarm+
       }?
   }

   type-eventprop = element properties {
       property-dtstamp &
       property-dtstart &
       property-uid &

       property-class? &
       property-created? &
       property-description? &
       property-geo? &
       property-last-mod? &
       property-location? &
       property-organizer? &
       property-priority? &
       property-seq? &
       property-status-event? &
       property-summary? &
       property-transp? &
       property-url? &
       property-recurid? &

       property-rrule? &

       (property-dtend | property-duration)? &

       property-attach* &
       property-attendee* &
       property-categories* &
       property-comment* &
       property-contact* &



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       property-exdate* &
       property-rstatus* &
       property-related* &
       property-resources* &
       property-rdate*
   }

   # 3.6.2 To-do Component

   component-vtodo = element vtodo {
       type-todoprop,
       element components {
           component-valarm+
       }?
   }

   type-todoprop = element properties {
       property-dtstamp &
       property-uid &

       property-class? &
       property-completed? &
       property-created? &
       property-description? &
       property-geo? &
       property-last-mod? &
       property-location? &
       property-organizer? &
       property-percent? &
       property-priority? &
       property-recurid? &
       property-seq? &
       property-status-todo? &
       property-summary? &
       property-url? &

       property-rrule? &

       (
           (property-dtstart?, property-dtend? ) |
           (property-dtstart, property-duration)?
       ) &

       property-attach* &
       property-attendee* &
       property-categories* &
       property-comment* &
       property-contact* &



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       property-exdate* &
       property-rstatus* &
       property-related* &
       property-resources* &
       property-rdate*
   }

   # 3.6.3 Journal Component

   component-vjournal = element vjournal {
       type-jourprop
   }

   type-jourprop = element properties {
       property-dtstamp &
       property-uid &

       property-class? &
       property-created? &
       property-dtstart? &
       property-last-mod? &
       property-organizer? &
       property-recurid? &
       property-seq? &
       property-status-jour? &
       property-summary? &
       property-url? &

       property-rrule? &

       property-attach* &
       property-attendee* &
       property-categories* &
       property-comment* &
       property-contact* &
       property-description? &
       property-exdate* &
       property-related* &
       property-rdate* &
       property-rstatus*
   }

   # 3.6.4 Free/Busy Component

   component-vfreebusy = element vfreebusy {
       type-fbprop
   }




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   type-fbprop = element properties {
       property-dtstamp &
       property-uid &

       property-contact? &
       property-dtstart? &
       property-dtend? &
       property-duration? &
       property-organizer? &
       property-url? &

       property-attendee* &
       property-comment* &
       property-freebusy* &
       property-rstatus*
   }

   # 3.6.5 Time Zone Component

   component-vtimezone = element vtimezone {
       element properties {
           property-tzid &

           property-last-mod? &
           property-tzuurl?
       },
       element components {
           (component-standard | component-daylight) &
           component-standard* &
           component-daylight*
       }
   }

   component-standard = element standard {
       type-tzprop
   }

   component-daylight = element daylight {
       type-tzprop
   }

   type-tzprop = element properties {
       property-dtstart &
       property-tzoffsetto &
       property-tzoffsetfrom &

       property-rrule? &




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       property-comment* &
       property-rdate* &
       property-tzname*
   }

   # 3.6.6 Alarm Component

   component-valarm = element valarm {
       audioprop | dispprop | emailprop
   }

   type-audioprop = element properties {
       property-action &
       property-trigger &

       (property-duration, property-repeat)? &

       property-attach?
   }

   type-dispprop = element properties {
       property-action &
       property-description &
       property-trigger &
       property-summary &

       property-attendee+ &

       (property-duration, property-repeat)? &

       property-attach*
   }

   type-emailprop = element properties {
       property-action &
       property-description &
       property-trigger &

       (property-duration, property-repeat)?
   }

   # 3.7 Calendar Properties

   # 3.7.1 Calendar Scale

   property-calscale = element calscale {

       element parameters { empty }?,



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       element text { "GREGORIAN" }
   }

   # 3.7.2 Method

   property-method = element method {

       element parameters { empty }?,

       value-text
   }

   # 3.7.3 Product Identifier

   property-prodid = element prodid {

       element parameters { empty }?,

       value-text
   }

   # 3.7.4 Version

   property-version = element version {

       element parameters { empty }?,

       value-text
   }

   # 3.8 Component Properties

   # 3.8.1 Descriptive Component Properties

   # 3.8.1.1 Attachment

   property-attach = element attach {

       element parameters {
           fmttypeparam? &
           encodingparam?
       }?,

       value-uri | value-binary
   }

   # 3.8.1.2 Categories




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   property-categories = element categories {

       element parameters {
           languageparam? &
       }?,

       value-text+
   }

   # 3.8.1.3 Classification

   property-class = element class {

       element parameters { empty }?,

       element text {
           "PUBLIC" |
           "PRIVATE" |
           "CONFIDENTIAL"
       }
   }

   # 3.8.1.4 Comment

   property-comment = element comment {

       element parameters {
           altrepparam? &
           languageparam?
       }?,

       value-text
   }

   # 3.8.1.5 Description

   property-description = element description {

       element parameters {
           altrepparam? &
           languageparam?
       }?,

       value-text
   }

   # 3.8.1.6 Geographic Position




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   property-geo = element geo {

       element parameters { empty }?,

       element value {
           element latitude  { text },
           element longitude { text }
       }
   }

   # 3.8.1.7 Location

   property-location = element location {

       element parameters {
           altrepparam? &
           languageparam?
       }?,

       value-text
   }

   # 3.8.1.8 Percent Complete

   property-percent = element percent-complete {

       element parameters { empty }?,

       value-integer
   }

   # 3.8.1.9 Priority

   property-priority = element priority {

       element parameters { empty }?,

       value-integer
   }

   # 3.8.1.10 Resources

   property-resources = element resources {

       element parameters {
           altrepparam? &
           languageparam?
       }?,



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       value-text+
   }

   # 3.8.1.11 Status

   property-status-event = element status {

       element parameters { empty }?,

       element text {
           "TENTATIVE" |
           "CONFIRMED" |
           "CANCELLED"
       }
   }

   property-status-todo = element status {

       element parameters { empty }?,

       element text {
           "NEEDS-ACTION" |
           "COMPLETED" |
           "IN-PROCESS" |
           "CANCELLED"
       }
   }

   property-status-jour = element status {

       element parameters { empty }?,

       element text {
           "DRAFT" |
           "FINAL" |
           "CANCELLED"
       }
   }

   # 3.8.1.12 Summary

   property-summary = element summary {

       element parameters {
           altrepparam? &
           languageparam?
       }?,




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       value-text
   }

   # 3.8.2 Date and Time Component Properties

   # 3.8.2.1 Date/Time Completed

   property-completed = element completed {

       element parameters { empty }?,

       value-date-time
   }

   # 3.8.2.2 Date/Time End

   property-dtend = element dtend {

       element parameters {
           tzidparam?
       }?,

       value-date-time |
       value-date
   }

   # 3.8.2.3 Date/Time Due

   property-due = element due {

       element parameters {
           tzidparam?
       }?,

       value-date-time |
       value-date
   }

   # 3.8.2.4 Date/Time Start

   property-dtstart = element dtstart {

       element parameters {
           tzidparam?
       }?,

       value-date-time |
       value-date



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   }

   # 3.8.2.5 Duration

   property-duration = element duration {

       element parameters { empty }?,

       value-duration
   }

   # 3.8.2.6 Free/Busy Time

   property-freebusy = element freebusy {

       element parameters {
           fbtypeparam?
       }?,


       value-period+
   }

   # 3.8.2.7 Time Transparency

   property-transp = element transp {

       element parameters { empty }?,

       element text {
           "OPAQUE" |
           "TRANSPARENT"
       }
   }

   # 3.8.3 Time Zone Component Properties

   # 3.8.3.1 Time Zone Identifier

   property-tzid = element tzid {

       element parameters { empty }?,

       value-text
   }

   # 3.8.3.2 Time Zone Name




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   property-tzname = element tzname {

       element parameters {
           languageparam?
       }?,

       value-text
   }

   # 3.8.3.3 Time Zone Offset From

   property-tzoffsetfrom = element tzoffsetfrom {

       element parameters { empty }?,

       value-utc-offset
   }

   # 3.8.3.4 Time Zone Offset To

   property-tzoffsetto = element tzoffsetto {

       element parameters { empty }?,

       value-utc-offset
   }

   # 3.8.3.5 Time Zone URL

   property-tzurl = element tzurl {

       element parameters { empty }?,

       value-uri
   }

   # 3.8.4 Relationship Component Properties

   # 3.8.4.1 Attendee

   property-attendee = element attendee {

       element parameters {
           cutypeparam? &
           memberparam? &
           roleparam? &
           partstatparam? &
           rsvpparam? &



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           deltoparam? &
           delfromparam? &
           sentbyparam? &
           cnparam? &
           dirparam? &
           languageparam?
       }?,

       value-cal-address
   }

   # 3.8.4.2 Contact

   property-contact = element contact {

       element parameters {
           altrepparam? &
           languageparam?
       }?,

       value-text
   }

   # 3.8.4.3 Organizer

   property-organizer = element organizer {

       element parameters {
           cnparam? &
           dirparam? &
           sentbyparam? &
           languageparam?
       }?,

       value-cal-address
   }

   # 3.8.4.4 Recurrence ID

   property-recurid = element recurrence-id {

       element parameters {
           tzidparam? &
           rangeparam?
       }?,

       value-date-time |
       value-date



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   }

   # 3.8.4.5 Related-To

   property-related = element related-to {

       element parameters {
           reltypeparam?
       }?,

       value-text
   }

   # 3.8.4.6 Uniform Resource Locator

   property-url = element url {

       element parameters { empty }?,

       value-uri
   }

   # 3.8.4.7 Unique Identifier

   property-uid = element uid {

       element parameters { empty }?,

       value-text
   }

   # 3.8.5 Recurrence Component Properties

   # 3.8.5.1 Exception Date/Times

   property-exdate = element exdate {

       element parameters {
           tzidparam?
       }?,

       value-date-time+ |
       value-date+
   }

   # 3.8.5.2 Recurrence Date/Times

   property-rdate = element rdate {



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       element parameters {
           tzidparam?
       }?,

       value-date-time+ |
       value-date+ |
       value-period+
   }

   # 3.8.5.3 Recurrence Rule

   property-rrule = element rrule {

       element parameters { empty }?,

       value-recur
   }

   # 3.8.6 Alarm Component Properties

   # 3.8.6.1 Action

   property-action = element action {

       element parameters { empty }?,

       element text {
           "AUDIO" |
           "DISPLAY" |
           "EMAIL"
       }
   }

   # 3.8.6.2 Repeat Count

   property-repeat = element repeat {

       element parameters { empty }?,

       value-integer
   }

   # 3.8.6.3 Trigger

   property-repeat = element repeat {

       (
           element parameters {



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               trigrelparam?
           }?,

           value-duration
       ) |
       (
           element parameters { empty }?,

           value-date-time
       )
   }

   # 3.8.7 Change Management Component Properties

   # 3.8.7.1 Date/Time Created

   property-created = element created {

       element parameters { empty }?,

       value-date-time
   }

   # 3.8.7.2 Date/Time Stamp

   property-dtstamp = element dtstamp {

       element parameters { empty }?,

       value-date-time
   }

   # 3.8.7.3 Last Modified

   property-last-mod = element last-modified {

       element parameters { empty }?,

       value-date-time
   }

   # 3.8.7.4 Sequence Number

   property-seq = element sequence {

       element parameters { empty }?,

       value-integer



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   }

   # 3.8.8 Miscellaneous Component Properties

   # 3.8.8.3 Request Status

   property-rstatus = element request-status {

       element parameters {
           languageparam?
       }?,

       element value {
           element code { text },
           element description { text },
           element data { text }?
       }
   }

Appendix B.  XML Stylesheet for conversion to iCalendar

   TO DO

Appendix C.  Example

   Below is some example iCalendar data and its representation in XML as
   defined by this specification.

C.1.  iCalendar Data

   BEGIN:VCALENDAR
   CALSCALE:GREGORIAN
   PRODID:-//Example Inc.//Example Calendar//EN
   VERSION:2.0
   BEGIN:VEVENT
   DTSTAMP:20080205T191224Z
   DTSTART:20081006
   SUMMARY:Planning meeting
   UID:4088E990AD89CB3DBB484909
   END:VEVENT
   END:VCALENDAR










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C.2.  XML Data

   <?xml version="1.0" encoding="utf-8"?>
   <icalendar xmlns="urn:ietf:params:xml:ns:icalendar">
    <vcalendar>
     <properties>
      <calscale><text>GREGORIAN</text></calscale>
      <prodid>
       <text>-//Example Inc.//Example Calendar//EN</text>
      </prodid>
      <version><text>2.0</text></version>
     </properties>
     <components>
      <vevent>
       <properties>
        <dtstamp>
         <date-time utc='yes'>
          <year>2008</year><month>2</month><day>5</day>
          <hour>19</hour><minute>12</minute><second>24</second>
         </date-time>
        </dtstamp>
        <dtstart>
         <date>
          <year>2008</year><month>10</month><day>6</day>
         </date>
        </dtstart>
        <summary>
         <text>Planning meeting</text>
        </summary>
        <uid>
         <text>4088E990AD89CB3DBB484909</text>
        </uid>
       </properties>
      </vevent>
     </components>
    </vcalendar>
   </icalendar>














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Authors' Addresses

   Cyrus Daboo
   Apple Inc.
   1 Infinite Loop
   Cupertino, CA  95014
   USA

   EMail: cyrus@daboo.name
   URI:   http://www.apple.com/


   Mike Douglass
   Rensselaer Polytechnic Institute
   110 8th Street
   Troy, NY  12180
   USA

   EMail: douglm@rpi.edu
   URI:   http://www.rpi.edu/


   Steven Lees
   Microsoft Corporation
   One Microsoft Way
   Redmond, WA  98052
   USA

   EMail: Steven.Lees@microsoft.com
   URI:   http://www.microsoft.com/





















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