Network Working Group C. Daboo
Internet-Draft Apple, Inc.
Intended status: Standards Track M. Douglass
Expires: April 16, 2011 RPI
S. Lees
Microsoft
October 13, 2010
xCal: The XML format for iCalendar
draft-daboo-et-al-icalendar-in-xml-07
Abstract
This specification defines "xCal", an XML format for iCalendar data.
Status of This Memo
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This Internet-Draft will expire on April 16, 2011.
Copyright Notice
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document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions Used in This Document . . . . . . . . . . . . . . 4
3. Converting from iCalendar to xCal . . . . . . . . . . . . . . 5
3.1. Pre-processing . . . . . . . . . . . . . . . . . . . . . . 5
3.2. iCalendar stream (RFC5545 section 3.4) . . . . . . . . . . 5
3.3. Components (RFC5545 section 3.6) . . . . . . . . . . . . . 6
3.4. Properties (RFC5545 section 3.7 and 3.8) . . . . . . . . . 7
3.4.1. Special Cases for Properties . . . . . . . . . . . . . 9
3.4.1.1. Multi-valued Properties . . . . . . . . . . . . . 9
3.4.1.2. GEO Property . . . . . . . . . . . . . . . . . . . 9
3.4.1.3. REQUEST-STATUS Property . . . . . . . . . . . . . 9
3.5. Parameters (RFC5545 section 3.2) . . . . . . . . . . . . . 10
3.5.1. VALUE parameter . . . . . . . . . . . . . . . . . . . 11
3.6. Values (RFC5545 section 3.3) . . . . . . . . . . . . . . . 11
3.6.1. Binary (RFC5545 section 3.3.1) . . . . . . . . . . . . 11
3.6.2. Boolean (RFC5545 section 3.3.2) . . . . . . . . . . . 12
3.6.3. Calendar User Address (RFC5545 section 3.3.3) . . . . 12
3.6.4. Date (RFC5545 section 3.3.4) . . . . . . . . . . . . . 12
3.6.5. Date-Time (RFC5545 section 3.3.5) . . . . . . . . . . 12
3.6.6. Duration (RFC5545 section 3.3.6) . . . . . . . . . . . 12
3.6.7. Float (RFC5545 section 3.3.7) . . . . . . . . . . . . 13
3.6.8. Integer (RFC5545 section 3.3.8) . . . . . . . . . . . 13
3.6.9. Period of Time (RFC5545 section 3.3.9) . . . . . . . . 13
3.6.10. Recurrence Rule (RFC5545 section 3.3.10) . . . . . . . 13
3.6.11. Text (RFC5545 section 3.3.11) . . . . . . . . . . . . 13
3.6.12. Time (RFC5545 section 3.3.12) . . . . . . . . . . . . 13
3.6.13. URI (RFC5545 section 3.3.13) . . . . . . . . . . . . . 14
3.6.14. UTC Offset (RFC5545 section 3.3.14) . . . . . . . . . 14
3.7. Extensions . . . . . . . . . . . . . . . . . . . . . . . . 14
4. Converting from XML into iCalendar . . . . . . . . . . . . . . 14
4.1. Converting XML Extensions into iCalendar . . . . . . . . . 14
4.2. The XML property for iCalendar . . . . . . . . . . . . . . 15
5. Security Considerations . . . . . . . . . . . . . . . . . . . 16
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
6.1. Namespace Registration . . . . . . . . . . . . . . . . . . 16
6.2. Media Type . . . . . . . . . . . . . . . . . . . . . . . . 17
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 18
8. Normative References . . . . . . . . . . . . . . . . . . . . . 18
Appendix A. Relax NG Schema . . . . . . . . . . . . . . . . . . . 18
Appendix B. Examples . . . . . . . . . . . . . . . . . . . . . . 41
B.1. Example 1 . . . . . . . . . . . . . . . . . . . . . . . . 41
B.1.1. iCalendar Data . . . . . . . . . . . . . . . . . . . . 41
B.1.2. XML Data . . . . . . . . . . . . . . . . . . . . . . . 42
B.2. Example 2 . . . . . . . . . . . . . . . . . . . . . . . . 42
B.2.1. iCalendar Data . . . . . . . . . . . . . . . . . . . . 43
B.2.2. XML Data . . . . . . . . . . . . . . . . . . . . . . . 43
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Appendix C. Change History (to be removed prior to
publication as an RFC) . . . . . . . . . . . . . . . 46
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1. Introduction
The iCalendar data format [RFC5545] 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 "xCal", an XML format
for iCalendar data. xCal is defined as a straightforward mapping into
XML from iCalendar, so that 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.
Key design considerations are:
Round-tripping (converting an iCalendar instance to XML and back)
will give the same result as the starting point.
Preserve the semantics of the iCalendar data. While a simple
consumer can easily browse the calendar data in XML, a full
understanding of iCalendar is still required in order to modify
and/or fully comprehend the calendar data.
Ability to handle many extensions to the underlying iCalendar
specification without requiring an update to this document.
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].
When XML element types in the namespace
"urn:ietf:params:xml:ns:icalendar-2.0" 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.
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3. Converting from iCalendar to xCal
This section describes how iCalendar data is converted to XML using a
simple mapping between the iCalendar data model and XML elements.
3.1. Pre-processing
iCalendar 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 [RFC5545]. 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 (RFC5545 section 3.4)
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.
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-2.0">
<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 xCal, "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
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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-2.0">
<vcalendar>
<properties>
...
</properties>
<components>
...
</components>
</vcalendar>
</icalendar>
+------------------+----------------+------------------+
| Item | XML element | XML Definition |
+------------------+----------------+------------------+
| iCalendar Stream | ICAL:icalendar | Appendix A # 3.4 |
| VCALENDAR | ICAL:vcalendar | Appendix A # 3.6 |
+------------------+----------------+------------------+
3.3. Components (RFC5545 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. Any iCalendar components added in the future
will be converted in the same way. As a non-normative reference, the
table below shows the current iCalendar components and their XML
equivalents.
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+-----------+----------------+--------------------+
| 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 (RFC5545 section 3.7 and 3.8)
iCalendar properties , whether they apply to the VCALENDAR object or
to a component, are handled in a consistent way in the xCal format.
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:
<?xml version="1.0" encoding="utf-8"?>
<icalendar xmlns="urn:ietf:params:xml:ns:icalendar-2.0">
<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. As
with components, the table is a non-normative reference and is not
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meant to be exclusive. Any iCalendar properties added in the future
will be converted using the same mapping rule.
+------------------+-----------------------+-----------------------+
| 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 |
| 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 |
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| 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
This section describes some properties that have special handling
when converting to XML.
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 |
+------------+-----------------+-----------------------+
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 xCal, 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 xCal, the value for the ICAL:request-status element is represented
by an ICAL:value element containing an ICAL:code element, and iCAL:
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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 (RFC5545 section 3.2)
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 xCal 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:
<?xml version="1.0" encoding="utf-8"?>
<icalendar xmlns="urn:ietf:params:xml:ns:icalendar-2.0">
<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.
As with components and properties, the table below is shown as a non-
normative reference. Any parameters added to iCalendar in the future
will be converted by the rule given above.
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+----------------+---------------------+---------------------+
| 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 [RFC5545]).
This parameter is not mapped to an xCal XML element. Instead, the
value type is handled by having different XML elements for each
value, and these appear inside of ICAL:property 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 (RFC5545 section 3.3)
In the typical case, iCalendar value types are mapped into XML
elements with a matching name in all lowercase. In the case of the
value for a recurrence rule (see below), iCalendar defines
"structured" values and these are mapped into separate child elements
for each value element.
3.6.1. Binary (RFC5545 section 3.3.1)
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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 (RFC5545 section 3.3.2)
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 (RFC5545 section 3.3.3)
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 (RFC5545 section 3.3.4)
Description: iCalendar DATE property values are represented by the
ICAL:date XML element. The content of the element is the same
date value specified by RFC5545.
XML Definition: Appendix A # 3.3.4
3.6.5. Date-Time (RFC5545 section 3.3.5)
Description: iCalendar DATE-TIME property values are represented by
the ICAL:date-time XML element. The content of the element is the
same date-time value specified by RFC5545.
XML Definition: Appendix A # 3.3.5
3.6.6. Duration (RFC5545 section 3.3.6)
Description: iCalendar DURATION property values are represented by
the ICAL:duration XML element. The content of the element is the
same duration value specified by RFC5545.
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XML Definition: Appendix A # 3.3.6
3.6.7. Float (RFC5545 section 3.3.7)
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 (RFC5545 section 3.3.8)
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
3.6.9. Period of Time (RFC5545 section 3.3.9)
Description: iCalendar PERIOD property values are represented by the
ICAL:period XML element. The content of the element is the same
period value specified by RFC5545.
XML Definition: Appendix A # 3.3.9
3.6.10. Recurrence Rule (RFC5545 section 3.3.10)
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 (RFC5545 section 3.3.11)
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 (RFC5545 section 3.3.12)
Description: iCalendar TIME property values are represented by the
ICAL:time XML element. The content of the element is the same
time value specified by RFC5545.
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XML Definition: Appendix A # 3.3.12
3.6.13. URI (RFC5545 section 3.3.13)
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 (RFC5545 section 3.3.14)
Description: iCalendar UTC-OFFSET property values are represented by
the ICAL:utc-offset XML element. The content of the element is
the same UTC offset value specified by RFC5545.
XML Definition: Appendix A # 3.3.14
3.7. Extensions
iCalendar extension properties and parameters (those 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 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 [RFC5545].
Backslash escaping and line folding MUST be applied to the resulting
iCalendar data as required by [RFC5545].
4.1. Converting XML Extensions into iCalendar
XML extensions are converted back to iCalendar in one of two ways,
depending on whether the extensions are in the iCalendar XML
namespace, or in an external namespace.
Extensions that are part of the iCalendar XML namespace MUST have
element names that being with "x-", and will be converted back to the
equivalent extension property in iCalendar. For example, the "x-foo"
element will convert to the "X-FOO" iCalendar property.
Extensions that are in a namespace other than the iCalendar XML
namespace SHOULD be preserved in the iCalendar representation using
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the XML iCalendar property described in Section 4.2.
4.2. The XML property for iCalendar
This section describes an extension property for iCalendar, as
covered in section 8.2.3 of [RFC5545].
Property name: XML
Purpose: To embed XML-encoded calendar data in the iCalendar format.
Value type: A single text value.
Property parameters: VALUE, ENCODING.
Conformance: The property can appear on any iCalendar component.
Description: The value of this property is an XML element. The XML
property MUST NOT be used to contain properties that are already
defined in iCalendar, or properties that use the "X-" iCalendar
extension property syntax. Since all elements in the
urn:ietf:params:xml:ns:icalendar-2.0 namespace convert to a well-
defined iCalendar object, the elements in this property MUST NOT be
in the urn:ietf:params:xml:ns:icalendar-2.0 namespace. The XML
element which is the value of this property MUST have an XML
namespace declaration.
Note that the source XML may contain characters not allowed in
iCalendar such as control characters. If this is the case, then the
XML data MUST be base64 encoded. As required by [RFC5545], the
ENCODING paramater MUST be present and set to "BASE64", and the VALUE
parameter must be present and set to "BINARY".
There can be more than one XML property present for a given iCalendar
object. The ordering of XML properties is not preserved in the
conversion between XML and iCalendar.
Format definition: This property is defined by the following
notation:
xml = "XML:" text CRLF
Example: The following is an example of an iCalendar event with a
location embedded in KML markup inside the XML property.
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BEGIN:VCALENDAR
CALSCALE:GREGORIAN
PRODID:-//Example Inc.//Example Calendar//EN
VERSION:2.0
BEGIN:VEVENT
DTSTAMP:20080205T191224Z
DTSTART:20081006
SUMMARY:Planning meeting
UID:4088E990AD89CB3DBB484909
XML:<kml xmlns="http://www.opengis.net/kml/2.2">...</kml>
END:VEVENT
END:VCALENDAR
5. Security Considerations
For security considerations specific to calendar data, see Section 7
of [RFC5545]. Since this specification is a mapping from iCalendar,
no new security concerns are introduced related to calendar data.
The use of XML as a format does have security risks. Section 7 of
[RFC3470] discusses these risks. See also the security disussion for
the application/xml type in [RFC3023].
6. IANA Considerations
This document defines a new URN to identify a new XML namespace for
iCalendar data. The URN conforms to a registry mechanism described
in [RFC3688].
This document defines a new media type. The registration is in
Section 6.2.
This document defines a new property for iCalendar. The registration
is in Section 4.2.
6.1. Namespace Registration
Registration request for the iCalendar namespace:
URI: urn:ietf:params:xml:ns:icalendar-2.0
Registrant Contact: See the "Authors' Addresses" section of this
document.
XML: None. Namespace URIs do not represent an XML specification.
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6.2. Media Type
This section defines the MIME media type for use with iCalendar in
XML data.
Type name: application
Subtype name: calendar+xml
Required parameters: none
Optional parameters: method, component and optinfo as defined for
the text/calendar media type in [RFC5545]; charset as defined for
application/xml in [RFC3023]; per [RFC3023], use of charset is
"STRONGLY RECOMMENDED"
Encoding considerations: Same as encoding considerations of
application/xml as specified in [RFC3023]
Security considerations: See Section 5.
Interoperability considerations: This media type provides an
alternative format for 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): xcs
Macintosh file type code(s): None specified.
Person & email address to contact for further information:
ietf-calsify@osafoundation.org
Intended usage: COMMON
Restrictions on usage: There are no restrictions on where this media
type can be used.
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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
[RFC2119] Bradner, S., "Key words for use in RFCs to
Indicate Requirement Levels", BCP 14,
RFC 2119, March 1997.
[RFC3023] Murata, M., St. Laurent, S., and D. Kohn,
"XML Media Types", RFC 3023, January 2001.
[RFC3470] Hollenbeck, S., Rose, M., and L. Masinter,
"Guidelines for the Use of Extensible Markup
Language (XML) within IETF Protocols",
BCP 70, RFC 3470, January 2003.
[RFC3688] Mealling, M., "The IETF XML Registry",
BCP 81, RFC 3688, January 2004.
[RFC5545] Desruisseaux, B., "Internet Calendaring and
Scheduling Core Object Specification
(iCalendar)", RFC 5545, September 2009.
[W3C.REC-xml-20081126] Sperberg-McQueen, C., Yergeau, F., Bray, T.,
Paoli, J., and E. Maler, "Extensible Markup
Language (XML) 1.0 (Fifth Edition)", World
Wide Web Consortium Recommendation REC-xml-
20081126, November 2008,
<http://www.w3.org/TR/2008/REC-xml-20081126>.
Appendix A. Relax NG Schema
Below is a Relax NG schema for iCalendar in XML. The schema is non-
normative and given for reference only.
This schema uses the compact notation of Relax NG. The numeric
section numbers given in the comments refer to section in [RFC5545].
The ordering of elements follows the section ordering of [RFC5545].
The Relax NG compact notation "?" operator is used to indicate an
unordered list of items. However, that operator, as defined, allows
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"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
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-2.0"
# 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"
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}
# 3.2.8 Format Type
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"
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)
type-partstat-jour = (
"NEEDS-ACTION" |
"ACCEPTED" |
"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 }
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# 3.2.19 Time Zone Identifier
tzidparam = element tzid { text }
# 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 {
text
}
# 3.3.5 DATE-TIME
value-date-time = element date-time {
text
}
# 3.3.6 DURATION
value-duration = element duration {
text
}
# 3.3.7 FLOAT
value-float = element float { text }
# 3.3.8 INTEGER
value-integer = element integer { text }
# 3.3.9 PERIOD
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value-period = element period {
text
}
# 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*,
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"
)
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type-byday = element byday {
text
}
type-bymonthday = element bymonthday {
text
}
type-byyearday = element byyearday {
text
}
type-byweekno = element byweekno {
text
}
type-bysetpos = element bysetpos {
text
}
# 3.3.11 TEXT
value-text = element text { text }
# 3.3.12 TIME
value-time = element time { text }
# 3.3.13 URI
value-uri = element uri { text }
# 3.3.14 UTC-OFFSET
value-utc-offset = element utc-offset { text }
# 3.4 iCalendar Stream
start = element icalendar { vcalendar+ }
# 3.6 Calendar Components
vcalendar = element vcalendar {
type-calprops,
type-component
}
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type-calprops = element properties {
property-prodid &
property-version &
property-calscale? &
property-method?
}
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? &
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(property-dtend | property-duration)? &
property-attach* &
property-attendee* &
property-categories* &
property-comment* &
property-contact* &
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)?
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) &
property-attach* &
property-attendee* &
property-categories* &
property-comment* &
property-contact* &
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*
}
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# 3.6.4 Free/Busy Component
component-vfreebusy = element vfreebusy {
type-fbprop
}
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 {
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property-dtstart &
property-tzoffsetto &
property-tzoffsetfrom &
property-rrule? &
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
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# 3.7.1 Calendar Scale
property-calscale = element calscale {
element parameters { empty }?,
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?
}?,
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value-uri | value-binary
}
# 3.8.1.2 Categories
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?
}?,
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value-text
}
# 3.8.1.6 Geographic Position
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 {
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element parameters {
altrepparam? &
languageparam?
}?,
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 {
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element parameters {
altrepparam? &
languageparam?
}?,
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 {
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tzidparam?
}?,
value-date-time |
value-date
}
# 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 }?,
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value-text
}
# 3.8.3.2 Time Zone Name
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 {
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cutypeparam? &
memberparam? &
roleparam? &
partstatparam? &
rsvpparam? &
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? &
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rangeparam?
}?,
value-date-time |
value-date
}
# 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+
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}
# 3.8.5.2 Recurrence Date/Times
property-rdate = element rdate {
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
}
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# 3.8.6.3 Trigger
property-repeat = element repeat {
(
element parameters {
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
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property-seq = element sequence {
element parameters { empty }?,
value-integer
}
# 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. Examples
This section contains two examples of iCalendar objects with their
xCal representation.
B.1. Example 1
B.1.1. 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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B.1.2. XML Data
<?xml version="1.0" encoding="utf-8"?>
<icalendar xmlns="urn:ietf:params:xml:ns:icalendar-2.0">
<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>20080205T191224Z</date-time></dtstamp>
<dtstart><date>20081006</date></dtstart>
<summary>
<text>Planning meeting</text>
</summary>
<uid>
<text>4088E990AD89CB3DBB484909</text>
</uid>
</properties>
</vevent>
</components>
</vcalendar>
</icalendar>
B.2. Example 2
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B.2.1. iCalendar Data
VERSION:2.0
PRODID:-//Example Corp.//Example Client//EN
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:US/Eastern
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20060206T001121Z
DTSTART;TZID=US/Eastern:20060102T120000
DURATION:PT1H
RRULE:FREQ=DAILY;COUNT=5
SUMMARY:Event #2
UID:00959BC664CA650E933C892C@example.com
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20060206T001121Z
DTSTART;TZID=US/Eastern:20060104T140000
DURATION:PT1H
RECURRENCE-ID;TZID=US/Eastern:20060104T120000
SUMMARY:Event #2 bis
UID:00959BC664CA650E933C892C@example.com
END:VEVENT
END:VCALENDAR
B.2.2. XML Data
<?xml version="1.0" encoding="utf-8" ?>
<icalendar xmlns="urn:ietf:params:xml:ns:icalendar-2.0">
<vcalendar>
<properties>
<prodid>
<text>-//Example Inc.//Example Client//EN</text>
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</prodid>
<version>
<text>2.0</text>
</version>
</properties>
<components>
<vtimezone>
<properties>
<last-modified>
<date-time>20040110T032845Z</date-time>
</last-modified>
<tzid>US/Eastern</tzid>
</properties>
<components>
<daylight>
<properties>
<dtstart>
<date-time>20000404T020000</date-time>
</dtstart>
<rrule>
<recur>
<freq>YEARLY</freq>
<byday>1SU</byday>
<bymonth>4</bymonth>
</recur>
</rrule>
<tzname>
<text>EDT</text>
</tzname>
<tzoffsetfrom>
<utc-offset>-0500</utc-offset>
</tzoffsetfrom>
<tzoffsetto>
<utc-offset>-0400</utc-offset>
</tzoffsetto>
</properties>
</daylight>
<standard>
<properties>
<dtstart>
<date-time>20001026T020000</date-time>
</dtstart>
<rrule>
<recur>
<freq>YEARLY</freq>
<byday>-1SU</byday>
<bymonth>10</bymonth>
</recur>
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</rrule>
<tzname>
<text>EST</text>
</tzname>
<tzoffsetfrom>
<utc-offset>-0400</utc-offset>
</tzoffsetfrom>
<tzoffsetto>
<utc-offset>-0500</utc-offset>
</tzoffsetto>
</properties>
</standard>
</components>
</vtimezone>
<vevent>
<properties>
<dtstamp><date-time>20060206T001121Z<date-time></dtstamp>
<dtstart>
<parameters>
<tzid>US/Eastern</tzid>
</parameters>
<date-time>20060102T120000</date-time>
</dtstart>
<duration>
<duration>PT1H</duration>
</duration>
<rrule>
<recur>
<freq>DAILY</freq>
<count>5</count>
</recur>
</rrule>
<summary>
<text>Event #2</text>
</summary>
<uid>
<text>00959BC664CA650E933C892C@example.com</text>
</uid>
</properties>
</vevent>
<vevent>
<properties>
<dtstamp><date-time>20060206T001121Z</date-time></dtstamp>
<dtstart>
<parameters>
<tzid>US/Eastern</tzid>
</parameters>
<date-time>20060104T140000</date-time>
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</dtstart>
<duration>
<duration>PT1H</duration>
</duration>
<recurrence-id>
<parameters>
<tzid>US/Eastern</tzid>
</parameters>
<date-time>20060104T120000</date-time>
</recurrence-id>
<summary>
<text>Event #2 bis</text>
</summary>
<uid>
<text>00959BC664CA650E933C892C@example.com</text>
</uid>
</properties>
</vevent>
</components>
</vcalendar>
</icalendar>
Appendix C. Change History (to be removed prior to publication as an
RFC)
Changes from -06:
1. Updated XML reference to latest version.
2. Corrected dtstamp elements in samples.
3. Removed empty informative references section.
4. Changed media type registration file extension to "xcs" (feedback
from ietf-types)
5. Changed media type registration follow up email to ietf-calsify
(feedback from ietf-types)
6. Updated several parts of the specification to show how future
extensions to iCalendar can be handled without changing this
specification (feedback from ietf-types)
7. Updated security concerns in section 5 (feedback from ietf-types)
8. Updated encoding considerations in section 5 (feedback from ietf-
types)
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Changes from -05:
1. Removed the ordwk and weekday elements from the byday element in
a recurrence rule. The byday element now takes a text value
which is the same as the value used in [RFC5545].
2. Added another example of an iCalendar object converted to xCal.
3. Fixed the MIME type registration (another instance of xml+
calendar corrected to calendar+xml).
Changes from -04:
1. Added description to XML extension discussing how to handle
binary data in XML.
2. Removed empty Appendix B.
Changes from -03:
1. Changed the proposed MIME type from xml+calendar to calendar+xml.
2. Fixed several references to sections of RFC5545.
3. Updated example in Appendix C.
4. Corrected the definition and grammar for TIME and UTC-OFFSET
properties.
Changes from -02:
1. Removed the LINK extension and related sections. The concept
will be addressed in a separate specification.
2. Various minor edits for clarity and consistency.
Changes from -01:
1. Added LINK extension to iCalendar and section discussing links in
XML format.
2. Adopted "xCal" as the short name for the specification.
Changes from -00:
1. Changed 2445bis references to RFC5545.
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2. Added a version number to the XML namespace for iCalendar.
3. Changed the values for the date, date-time, period, and duration
elements to exactly match the values specified in RFC5545.
Previously these were broken out into separate elements for day,
month, year, etc.
4. Added specification for XML property in iCalendar.
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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