draft-ietf-calext-extensions-05.txt   rfc7986.txt 
Network Working Group C. Daboo Internet Engineering Task Force (IETF) C. Daboo
Internet-Draft Apple Inc. Request for Comments: 7986 Apple Inc.
Updates: 5545 (if approved) August 22, 2016 Updates: 5545 October 2016
Intended status: Standards Track Category: Standards Track
Expires: February 23, 2017 ISSN: 2070-1721
New Properties for iCalendar New Properties for iCalendar
draft-ietf-calext-extensions-05
Abstract Abstract
This document defines a set of new properties for iCalendar data as This document defines a set of new properties for iCalendar data and
well as extending the use of some existing properties to the entire extends the use of some existing properties to the entire iCalendar
iCalendar object. object.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
This Internet-Draft will expire on February 23, 2017. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7986.
Copyright Notice Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction ....................................................3
2. Conventions Used in This Document . . . . . . . . . . . . . . 3 2. Conventions Used in This Document ...............................3
3. Backwards Compatible Extension Properties . . . . . . . . . . 3 3. Backwards-Compatible Extension Properties .......................3
4. Modifications to Calendar Components . . . . . . . . . . . . 3 4. Modifications to Calendar Components ............................4
5. Properties . . . . . . . . . . . . . . . . . . . . . . . . . 5 5. Properties ......................................................5
5.1. NAME Property . . . . . . . . . . . . . . . . . . . . . . 5 5.1. NAME Property ..............................................5
5.2. DESCRIPTION Property . . . . . . . . . . . . . . . . . . 6 5.2. DESCRIPTION Property .......................................6
5.3. UID Property . . . . . . . . . . . . . . . . . . . . . . 6 5.3. UID Property ...............................................7
5.4. LAST-MODIFIED Property . . . . . . . . . . . . . . . . . 7 5.4. LAST-MODIFIED Property .....................................8
5.5. URL Property . . . . . . . . . . . . . . . . . . . . . . 8 5.5. URL Property ...............................................8
5.6. CATEGORIES Property . . . . . . . . . . . . . . . . . . . 8 5.6. CATEGORIES Property ........................................8
5.7. REFRESH-INTERVAL Property . . . . . . . . . . . . . . . . 8 5.7. REFRESH-INTERVAL Property ..................................9
5.8. SOURCE Property . . . . . . . . . . . . . . . . . . . . . 9 5.8. SOURCE Property ...........................................10
5.9. COLOR Property . . . . . . . . . . . . . . . . . . . . . 10 5.9. COLOR Property ............................................10
5.10. IMAGE Property . . . . . . . . . . . . . . . . . . . . . 11 5.10. IMAGE Property ...........................................11
5.11. CONFERENCE Property . . . . . . . . . . . . . . . . . . . 12 5.11. CONFERENCE Property ......................................13
6. Property Parameters . . . . . . . . . . . . . . . . . . . . . 14 6. Property Parameters ............................................14
6.1. DISPLAY Property Parameter . . . . . . . . . . . . . . . 14 6.1. DISPLAY Property Parameter ................................14
6.2. EMAIL Property Parameter . . . . . . . . . . . . . . . . 15 6.2. EMAIL Property Parameter ..................................15
6.3. FEATURE Property Parameter . . . . . . . . . . . . . . . 16 6.3. FEATURE Property Parameter ................................16
6.4. LABEL Property Parameter . . . . . . . . . . . . . . . . 17 6.4. LABEL Property Parameter ..................................17
7. Security Considerations . . . . . . . . . . . . . . . . . . . 17 7. Security Considerations ........................................18
8. Privacy Considerations . . . . . . . . . . . . . . . . . . . 18 8. Privacy Considerations .........................................18
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 9. IANA Considerations ............................................19
9.1. Property Registrations . . . . . . . . . . . . . . . . . 19 9.1. Property Registrations ....................................19
9.2. Parameter Registrations . . . . . . . . . . . . . . . . . 20 9.2. Parameter Registrations ...................................20
9.3. Property Parameter Value Registries . . . . . . . . . . . 20 9.3. Property Parameter Value Registries .......................20
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 21 10. References ....................................................21
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 21 10.1. Normative References .....................................21
11.1. Normative References . . . . . . . . . . . . . . . . . . 21 10.2. Informative References ...................................22
11.2. Informative References . . . . . . . . . . . . . . . . . 22 Acknowledgments ...................................................23
Appendix A. Change History (To be removed by RFC Editor before Author's Address ..................................................23
publication) . . . . . . . . . . . . . . . . . . . . 22
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 26
1. Introduction 1. Introduction
The iCalendar [RFC5545] data format is used to represent calendar The iCalendar [RFC5545] data format is used to represent calendar
data and is used with iTIP [RFC5546] to handle scheduling operations data and is used with the iCalendar Transport-Independent
between calendar users. iCalendar is in widespread use, and in Interoperability Protocol (iTIP) [RFC5546] to handle scheduling
accordance with provisions in that specification, extension elements operations between calendar users. iCalendar is in widespread use,
have been added by various vendors to the data format in order to and in accordance with provisions in that specification, extension
support and enhance capabilities. This specification collects a elements have been added by various vendors to the data format in
number of these ad-hoc extensions and uses the new IANA registry order to support and enhance capabilities. This specification
capability defined in [RFC5545] to register standard variants with collects a number of these ad hoc extensions and uses the new IANA
clearly defined definitions and semantics. In addition, some new registry capability defined in [RFC5545] to register standard
elements are introduced for features that vendors have recently been variants with clearly defined definitions and semantics. In
requesting. addition, some new elements are introduced for features that vendors
have recently been requesting.
2. Conventions Used in This Document 2. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in "OPTIONAL" in this document are to be interpreted as described in
[RFC2119]. [RFC2119].
The notation used in this memo is the ABNF notation of [RFC5234] as The notation used in this memo is the ABNF notation of [RFC5234] as
used by iCalendar [RFC5545]. Any syntax elements shown below that used by iCalendar [RFC5545]. Any syntax elements shown below that
are not explicitly defined in this specification come from iCalendar are not explicitly defined in this specification come from iCalendar
[RFC5545]. [RFC5545].
3. Backwards Compatible Extension Properties 3. Backwards-Compatible Extension Properties
iCalendar defines properties which can have different value types iCalendar defines properties that can have different value types
indicated by a "VALUE" parameter. The definition of a property indicated by a "VALUE" parameter. The definition of a property
specifies a "default" value type that is assumed to be used when no specifies a "default" value type that is assumed to be used when no
"VALUE" parameter is present. However, this poses a problem to "VALUE" parameter is present. However, this poses a problem to the
iCalendar parser/generator software that does not know about the iCalendar parser/generator software that does not know about the
default values for new properties. For example, if a new property default values for new properties. For example, if a new property
"FOO" were defined with a default value type of URI, and a URI value "FOO" were defined with a default value type of URI and a URI value
with a comma was used, an iCalendar generator not aware of this fact with a comma was used, an iCalendar generator not aware of this fact
would likely treat the property value as "TEXT" and apply backslash would likely treat the property value as "TEXT" and apply backslash
escaping to the comma in the value, effectively making it an invalid escaping to the comma in the value, effectively making it an invalid
URI value. URI value.
To avoid this problem, this specification recommends that all To avoid this problem, this specification recommends that all
properties not defined in [RFC5545], always include a "VALUE" properties not defined in [RFC5545] always include a "VALUE"
parameter, if the type is other than "TEXT". i.e., in the example parameter if the type is other than "TEXT". That is, in the example
above, the "FOO" property would have a "VALUE=URI" parameter. This above, the "FOO" property would have a "VALUE=URI" parameter. This
allows iCalendar parser/generator software to track the correct types allows iCalendar parser/generator software to track the correct types
of unknown properties. of unknown properties.
New properties defined in this specification use the term "no New properties defined in this specification use the term "no
default" in the "Value Type" definition to indicate that the "VALUE" default" in the "Value Type" definition to indicate that the "VALUE"
parameter has to be included. parameter has to be included.
4. Modifications to Calendar Components 4. Modifications to Calendar Components
The following changes to the syntax defined in iCalendar [RFC5545] This section details changes to the syntax defined in iCalendar
are made here. New elements are defined in subsequent sections. [RFC5545]. New elements are defined in subsequent sections.
calprops =/ *( calprops =/ *(
; ;
; The following are OPTIONAL, ; The following are OPTIONAL,
; but MUST NOT occur more than once. ; but MUST NOT occur more than once.
; ;
uid / last-mod / url / uid / last-mod / url /
refresh / source / color refresh / source / color
; ;
; The following are OPTIONAL, ; The following are OPTIONAL,
skipping to change at page 6, line 28 skipping to change at page 6, line 31
; ;
) )
Example: The following is an example of this property: Example: The following is an example of this property:
NAME:Company Vacation Days NAME:Company Vacation Days
5.2. DESCRIPTION Property 5.2. DESCRIPTION Property
This specification modifies the definition of the "DESCRIPTION" This specification modifies the definition of the "DESCRIPTION"
property to allow it to be defined on an iCalendar object. The property to allow it to be defined in an iCalendar object. The
following additions are made to the definition of this property, following additions are made to the definition of this property,
originally specified in Section 3.8.1.5 of [RFC5545]. originally specified in Section 3.8.1.5 of [RFC5545].
Purpose: This property specifies the description of the calendar. Purpose: This property specifies the description of the calendar.
Conformance: This property can be specified multiple times in an Conformance: This property can be specified multiple times in an
iCalendar object. However, each property MUST represent the iCalendar object. However, each property MUST represent the
description of the calendar in a different language. description of the calendar in a different language.
Description: This property is used to specify a lengthy textual Description: This property is used to specify a lengthy textual
description of the iCalendar object that can be used by calendar description of the iCalendar object that can be used by calendar
user agents when describing the nature of the calendar data to a user agents when describing the nature of the calendar data to a
user. Whilst a calendar only has a single description, multiple user. Whilst a calendar only has a single description, multiple
language variants can be specified by including this property language variants can be specified by including this property
multiple times with different "LANGUAGE" parameter values on each. multiple times with different "LANGUAGE" parameter values on each.
5.3. UID Property 5.3. UID Property
This specification modifies the definition of the "UID" property to This specification modifies the definition of the "UID" property to
allow it to be defined on an iCalendar object. The following allow it to be defined in an iCalendar object. The following
additions are made to the definition of this property, originally additions are made to the definition of this property, originally
specified in Section 3.8.4.7 of [RFC5545]. specified in Section 3.8.4.7 of [RFC5545].
Purpose: This property specifies the persistent, globally unique Purpose: This property specifies the persistent, globally unique
identifier for the iCalendar object. This can be used, for identifier for the iCalendar object. This can be used, for
example, to identify duplicate calendar streams that a client may example, to identify duplicate calendar streams that a client may
have been given access to. It can be used in conjunction with the have been given access to. It can be used in conjunction with the
"LAST-MODIFIED" property also specified on the "VCALENDAR" object, "LAST-MODIFIED" property also specified on the "VCALENDAR" object
to identify the most recent version of a calendar. to identify the most recent version of a calendar.
Conformance: This property can be specified once in an iCalendar Conformance: This property can be specified once in an iCalendar
object. object.
The description of the "UID" property in [RFC5545] contains some The description of the "UID" property in [RFC5545] contains some
recommendations on how the value can be constructed. In particular, recommendations on how the value can be constructed. In particular,
it suggests use of host names, IP addresses, and domain names to it suggests use of host names, IP addresses, and domain names to
construct the value. However, this is no longer considered good construct the value. However, this is no longer considered good
practice, particularly from a security and privacy standpoint, since practice, particularly from a security and privacy standpoint, since
use of such values can leak key information about a calendar user, or use of such values can leak key information about a calendar user or
their client and network environment. This specification updates their client and network environment. This specification updates
[RFC5545] by stating that "UID" values MUST NOT include any data that [RFC5545] by stating that "UID" values MUST NOT include any data that
might identify a user, host, domain, or any other security or privacy might identify a user, host, domain, or any other security- or
sensitive information. It is RECOMMENDED that calendar user agents privacy-sensitive information. It is RECOMMENDED that calendar user
now generate "UID" values that are hex-encoded random UUID values as agents now generate "UID" values that are hex-encoded random
defined in Sections 4.4 and 4.5 of [RFC4122]. Universally Unique Identifier (UUID) values as defined in
Sections 4.4 and 4.5 of [RFC4122].
The following is an example of such a property value: The following is an example of such a property value:
UID:5FC53010-1267-4F8E-BC28-1D7AE55A7C99 UID:5FC53010-1267-4F8E-BC28-1D7AE55A7C99
Additionally, if calendar user agents choose to use other forms of Additionally, if calendar user agents choose to use other forms of
opaque identifiers for the "UID" value, they MUST have a length less opaque identifiers for the "UID" value, they MUST have a length less
than 255 octets, and MUST conform to the "iana-token" ABNF syntax than 255 octets and MUST conform to the "iana-token" ABNF syntax
defined in Section 3.1 of [RFC5545]. defined in Section 3.1 of [RFC5545].
5.4. LAST-MODIFIED Property 5.4. LAST-MODIFIED Property
This specification modifies the definition of the "LAST-MODIFIED" This specification modifies the definition of the "LAST-MODIFIED"
property to allow it to be defined on an iCalendar object. The property to allow it to be defined in an iCalendar object. The
following additions are made to the definition of this property, following additions are made to the definition of this property,
originally specified in Section 3.8.7.3 of [RFC5545]. originally specified in Section 3.8.7.3 of [RFC5545].
Purpose: This property specifies the date and time that the Purpose: This property specifies the date and time that the
information associated with the calendar was last revised. information associated with the calendar was last revised.
Conformance: This property can be specified once in an iCalendar Conformance: This property can be specified once in an iCalendar
object. object.
5.5. URL Property 5.5. URL Property
This specification modifies the definition of the "URL" property to This specification modifies the definition of the "URL" property to
allow it to be defined on an iCalendar object. The following allow it to be defined in an iCalendar object. The following
additions are made to the definition of this property, originally additions are made to the definition of this property, originally
specified in Section 3.8.4.6 of [RFC5545]. specified in Section 3.8.4.6 of [RFC5545].
Purpose: This property may be used to convey a location where a more Purpose: This property may be used to convey a location where a more
dynamic rendition of the calendar information can be found. dynamic rendition of the calendar information can be found.
Conformance: This property can be specified once in an iCalendar Conformance: This property can be specified once in an iCalendar
object. object.
5.6. CATEGORIES Property 5.6. CATEGORIES Property
This specification modifies the definition of the "CATEGORIES" This specification modifies the definition of the "CATEGORIES"
property to allow it to be defined on an iCalendar object. The property to allow it to be defined in an iCalendar object. The
following additions are made to the definition of this property, following additions are made to the definition of this property,
originally specified in Section 3.8.1.2 of [RFC5545]. originally specified in Section 3.8.1.2 of [RFC5545].
Purpose: This property defines the categories for an entire Purpose: This property defines the categories for an entire
calendar. calendar.
Conformance: This property can be specified multiple times in an Conformance: This property can be specified multiple times in an
iCalendar object. iCalendar object.
Description: When multiple properties are present, the set of Description: When multiple properties are present, the set of
skipping to change at page 8, line 43 skipping to change at page 9, line 13
the categories listed in each property value. the categories listed in each property value.
5.7. REFRESH-INTERVAL Property 5.7. REFRESH-INTERVAL Property
Property Name: REFRESH-INTERVAL Property Name: REFRESH-INTERVAL
Purpose: This property specifies a suggested minimum interval for Purpose: This property specifies a suggested minimum interval for
polling for changes of the calendar data from the original source polling for changes of the calendar data from the original source
of that data. of that data.
Value Type: DURATION - no default Value Type: DURATION -- no default
Property Parameters: IANA and non-standard property parameters can Property Parameters: IANA and non-standard property parameters can
be specified on this property. be specified on this property.
Conformance: This property can be specified once in an iCalendar Conformance: This property can be specified once in an iCalendar
object. object.
Description: This property specifies a positive duration that gives Description: This property specifies a positive duration that gives
a suggested minimum polling interval for checking for updates to a suggested minimum polling interval for checking for updates to
the calendar data. The value of this property SHOULD be used by the calendar data. The value of this property SHOULD be used by
skipping to change at page 9, line 37 skipping to change at page 10, line 9
) )
Example: The following is an example of this property: Example: The following is an example of this property:
REFRESH-INTERVAL;VALUE=DURATION:P1W REFRESH-INTERVAL;VALUE=DURATION:P1W
5.8. SOURCE Property 5.8. SOURCE Property
Property Name: SOURCE Property Name: SOURCE
Purpose: This property identified a URI where calendar data can be Purpose: This property identifies a URI where calendar data can be
refreshed from. refreshed from.
Value Type: URI - no default Value Type: URI -- no default
Property Parameters: IANA and non-standard property parameters can Property Parameters: IANA and non-standard property parameters can
be specified on this property. be specified on this property.
Conformance: This property can be specified once in an iCalendar Conformance: This property can be specified once in an iCalendar
object. object.
Description: This property identifies a location where a client can Description: This property identifies a location where a client can
retrieve updated data for the calendar. Clients SHOULD honor any retrieve updated data for the calendar. Clients SHOULD honor any
specified "REFRESH-INTERVAL" value when periodically retrieving specified "REFRESH-INTERVAL" value when periodically retrieving
data. Note that this property differs from the "URL" property in data. Note that this property differs from the "URL" property in
that "URL" is meant to provide an alternative representation of that "URL" is meant to provide an alternative representation of
the calendar data, rather than the original location of the data. the calendar data rather than the original location of the data.
Format Definition: This property is defined by the following Format Definition: This property is defined by the following
notation: notation:
source = "SOURCE" sourceparam ":" uri CRLF source = "SOURCE" sourceparam ":" uri CRLF
sourceparam = *(";" other-param) sourceparam = *(";" other-param)
Example: The following is an example of this property: Example: The following is an example of this property:
skipping to change at page 10, line 31 skipping to change at page 10, line 51
Purpose: This property specifies a color used for displaying the Purpose: This property specifies a color used for displaying the
calendar, event, todo, or journal data. calendar, event, todo, or journal data.
Value Type: TEXT Value Type: TEXT
Property Parameters: IANA and non-standard property parameters can Property Parameters: IANA and non-standard property parameters can
be specified on this property. be specified on this property.
Conformance: This property can be specified once in an iCalendar Conformance: This property can be specified once in an iCalendar
object, or "VEVENT", "VTODO", or "VJOURNAL" calendar components. object or in "VEVENT", "VTODO", or "VJOURNAL" calendar components.
Description: This property specifies a color that clients MAY use Description: This property specifies a color that clients MAY use
when presenting the relevant data to a user. Typically this would when presenting the relevant data to a user. Typically, this
appear as the "background" color of events or tasks. The value is would appear as the "background" color of events or tasks. The
a case-insensitive color name taken from the CSS3 set of names, value is a case-insensitive color name taken from the CSS3 set of
defined in Section 4.3 of [W3C.REC-css3-color-20110607]. names, defined in Section 4.3 of [W3C.REC-css3-color-20110607].
Format Definition: This property is defined by the following Format Definition: This property is defined by the following
notation: notation:
color = "COLOR" colorparam ":" text CRLF color = "COLOR" colorparam ":" text CRLF
; Value is CSS3 color name ; Value is CSS3 color name
colorparam = *(";" other-param) colorparam = *(";" other-param)
Example: The following is an example of this property: Example: The following is an example of this property:
COLOR:turquoise COLOR:turquoise
5.10. IMAGE Property 5.10. IMAGE Property
Property Name: IMAGE Property Name: IMAGE
Purpose: This property specifies an image associated with the Purpose: This property specifies an image associated with the
calendar or a calendar component. calendar or a calendar component.
Value Type: URI or BINARY - no default. The value MUST refer to or Value Type: URI or BINARY -- no default. The value MUST be data
be data with a media type of "image". with a media type of "image" or refer to such data.
Property Parameters: IANA, non-standard, display, inline encoding, Property Parameters: IANA, non-standard, display, inline encoding,
and value data type property parameters can be specified on this and value data type property parameters can be specified on this
property. The format type parameter can be specified on this property. The format type parameter can be specified on this
property and is RECOMMENDED for inline binary encoded content property and is RECOMMENDED for inline binary-encoded content
information. information.
Conformance: This property can be specified multiple times in an Conformance: This property can be specified multiple times in an
iCalendar object, or "VEVENT", "VTODO", or "VJOURNAL" calendar iCalendar object or in "VEVENT", "VTODO", or "VJOURNAL" calendar
components. components.
Description: This property specifies an image for an iCalendar Description: This property specifies an image for an iCalendar
object or a calendar component via a uri or directly with inline object or a calendar component via a URI or directly with inline
data that can be used by calendar user agents when presenting the data that can be used by calendar user agents when presenting the
calendar data to a user. Multiple properties MAY be used to calendar data to a user. Multiple properties MAY be used to
specify alternative sets of images with, for example, varying specify alternative sets of images with, for example, varying
media subtypes, resolutions or sizes. When multiple properties media subtypes, resolutions, or sizes. When multiple properties
are present, calendar user agents SHOULD display only one of them, are present, calendar user agents SHOULD display only one of them,
picking one that provides the most appropriate image quality, or picking one that provides the most appropriate image quality, or
display none. The "DISPLAY" parameter is used to indicate the display none. The "DISPLAY" parameter is used to indicate the
intended display mode for the image. The "ALTREP" parameter, intended display mode for the image. The "ALTREP" parameter,
defined in [RFC5545], can be used to provide a "clickable" image defined in [RFC5545], can be used to provide a "clickable" image
where the URI in the parameter value can be "launched" by a click where the URI in the parameter value can be "launched" by a click
on the image in the calendar user agent. on the image in the calendar user agent.
Format Definition: This property is defined by the following Format Definition: This property is defined by the following
notation: notation:
skipping to change at page 12, line 51 skipping to change at page 13, line 12
IMAGE;VALUE=URI;DISPLAY=BADGE;FMTTYPE=image/png:h IMAGE;VALUE=URI;DISPLAY=BADGE;FMTTYPE=image/png:h
ttp://example.com/images/party.png ttp://example.com/images/party.png
5.11. CONFERENCE Property 5.11. CONFERENCE Property
Property Name: CONFERENCE Property Name: CONFERENCE
Purpose: This property specifies information for accessing a Purpose: This property specifies information for accessing a
conferencing system. conferencing system.
Value Type: URI - no default. Value Type: URI -- no default.
Property Parameters: IANA, non-standard, feature, and label property Property Parameters: IANA, non-standard, feature, and label property
parameters can be specified on this property. parameters can be specified on this property.
Conformance: This property can be specified multiple times in a Conformance: This property can be specified multiple times in a
"VEVENT" or "VTODO" calendar component. "VEVENT" or "VTODO" calendar component.
Description: This property specifies information for accessing a Description: This property specifies information for accessing a
conferencing system for attendees of a meeting or task. This conferencing system for attendees of a meeting or task. This
might be for a telephone-based conference number dial-in with might be for a telephone-based conference number dial-in with
access codes included (such as a tel: URI [RFC3966] or a sip: or access codes included (such as a tel: URI [RFC3966] or a sip: or
sips: URI [RFC3261]), or it might be for a web-based video chat sips: URI [RFC3261]), for a web-based video chat (such as an http:
(such as an http: or https: URI [RFC7230]), or a URI for an or https: URI [RFC7230]), or for an instant messaging group chat
instant messaging group chat room (such as an xmpp: URI room (such as an xmpp: URI [RFC5122]). If a specific URI for a
[RFC5122]). If a specific URI for a conferencing system is not conferencing system is not available, a data: URI [RFC2397]
available, a data: URI [RFC2397] containing a text description can containing a text description can be used.
be used.
A conference system can be a bi-directional communication channel, A conference system can be a bidirectional communication channel
or a uni-directional "broadcast feed". or a uni-directional "broadcast feed".
The "FEATURE" property parameter is used to describe the key The "FEATURE" property parameter is used to describe the key
capabilities of the conference system to allow a client to choose capabilities of the conference system to allow a client to choose
the ones that give the required level of interaction from a set of the ones that give the required level of interaction from a set of
multiple properties. multiple properties.
The "LABEL" property paramater is used to convey additional The "LABEL" property parameter is used to convey additional
details on the use of the URI. For example, the URIs or access details on the use of the URI. For example, the URIs or access
codes for the moderator and attendee of a teleconference system codes for the moderator and attendee of a teleconference system
could be different, and the "LABEL" property parameter could be could be different, and the "LABEL" property parameter could be
used to "tag" each "CONFERENCE" property to indicate which is used to "tag" each "CONFERENCE" property to indicate which is
which. which.
The "LANGUAGE" property parameter can be used to specify the The "LANGUAGE" property parameter can be used to specify the
language used for text values used with this property (as per language used for text values used with this property (as per
Section 3.2.10 of [RFC5545]. Section 3.2.10 of [RFC5545]).
Format Definition: This property is defined by the following Format Definition: This property is defined by the following
notation: notation:
conference = "CONFERENCE" confparam ":" uri CRLF conference = "CONFERENCE" confparam ":" uri CRLF
confparam = *( confparam = *(
; ;
; The following is REQUIRED, ; The following is REQUIRED,
; but MUST NOT occur more than once. ; but MUST NOT occur more than once.
skipping to change at page 15, line 17 skipping to change at page 15, line 20
displayval = ("BADGE" / ; image inline with the title of the displayval = ("BADGE" / ; image inline with the title of the
; event ; event
"GRAPHIC" / ; a full image replacement for the event "GRAPHIC" / ; a full image replacement for the event
; itself ; itself
"FULLSIZE" / ; an image that is used to enhance the "FULLSIZE" / ; an image that is used to enhance the
; event ; event
"THUMBNAIL" / ; a smaller variant of "FULLSIZE" to be "THUMBNAIL" / ; a smaller variant of "FULLSIZE" to be
; used when space for the image is ; used when space for the image is
; constrained ; constrained
x-name / ; Experimental type x-name / ; Experimental type
iana-token) ; Other IANA registered type iana-token) ; Other IANA-registered type
; ;
; Default is BADGE ; Default is BADGE
Description: This property parameter MAY be specified on "IMAGE" Description: This property parameter MAY be specified on "IMAGE"
properties. In the absence of this parameter, the default value properties. In the absence of this parameter, the default value
"BADGE" MUST be used. The value determines how a client ought to "BADGE" MUST be used. The value determines how a client ought to
present an image supplied in iCalendar data to the user. present an image supplied in iCalendar data to the user.
Values for this parameter are registered with IANA as per Values for this parameter are registered with IANA as per
Section 9.3.1. New values can be added to this registry following Section 9.3.1. New values can be added to this registry following
skipping to change at page 15, line 49 skipping to change at page 16, line 4
Parameter Name: EMAIL Parameter Name: EMAIL
Purpose: To specify an email address that is used to identify or Purpose: To specify an email address that is used to identify or
contact an organizer or attendee. contact an organizer or attendee.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
emailparam = "EMAIL" "=" param-value emailparam = "EMAIL" "=" param-value
Description: This property parameter MAY be specified on "ORGANIZER" Description: This property parameter MAY be specified on "ORGANIZER"
or "ATTENDEE" properties. This property can be used in situations or "ATTENDEE" properties. This property can be used in situations
where the calendar user address value of "ORGANIZER" and where the calendar user address value of the "ORGANIZER" and
"ATTENDEE" properties is not likely to be an identifier that "ATTENDEE" properties is not likely to be an identifier that
recipients of scheduling messages could use to match the calendar recipients of scheduling messages could use to match the calendar
user with, for example, an address book entry. The value of this user with, for example, an address book entry. The value of this
property is an email address that can easily be matched by property is an email address that can easily be matched by
recipients. Recipients can also use this value as an alternative recipients. Recipients can also use this value as an alternative
means of contacting the calendar user via email. If a recipient's means of contacting the calendar user via email. If a recipient's
calendar user agent allows the recipient to save contact calendar user agent allows the recipient to save contact
information based on the "ORGANIZER" or "ATTENDEE" properties, information based on the "ORGANIZER" or "ATTENDEE" properties,
those calendar user agents SHOULD use any "EMAIL" property those calendar user agents SHOULD use any "EMAIL" property
parameter value for the email address of the contact over any parameter value for the email address of the contact over any
skipping to change at page 16, line 43 skipping to change at page 16, line 46
featureparam = "FEATURE" "=" featuretext *("," featuretext) featureparam = "FEATURE" "=" featuretext *("," featuretext)
featuretext = ("AUDIO" / ; Audio capability featuretext = ("AUDIO" / ; Audio capability
"CHAT" / ; Chat or instant messaging "CHAT" / ; Chat or instant messaging
"FEED" / ; Blog or Atom feed "FEED" / ; Blog or Atom feed
"MODERATOR" / ; Moderator dial-in code "MODERATOR" / ; Moderator dial-in code
"PHONE" / ; Phone conference "PHONE" / ; Phone conference
"SCREEN" / ; Screen sharing "SCREEN" / ; Screen sharing
"VIDEO" / ; Video capability "VIDEO" / ; Video capability
x-name / ; Experimental type x-name / ; Experimental type
iana-token) ; Other IANA registered type iana-token) ; Other IANA-registered type
Description: This property parameter MAY be specified on the Description: This property parameter MAY be specified on the
"CONFERENCE" property. Multiple values can be specified. The "CONFERENCE" property. Multiple values can be specified. The
"MODERATOR" value is used to indicate that the property value is "MODERATOR" value is used to indicate that the property value is
specific to the owner/initiator of the conference and contains a specific to the owner/initiator of the conference and contains a
URI that "activates" the system (e.g., a "moderator" access code URI that "activates" the system (e.g., a "moderator" access code
for a phone conference system that is different from the "regular" for a phone conference system that is different from the "regular"
access code). access code).
Example: Example:
CONFERENCE;VALUE=URI;FEATURE=AUDIO:rtsp://audio.example.com/ CONFERENCE;VALUE=URI;FEATURE=AUDIO:rtsp://audio.example.com/
event event
CONFERENCE;VALUE=URI;FEATURE=AUDIO,VIDEO:https://video-chat.exam CONFERENCE;VALUE=URI;FEATURE=AUDIO,VIDEO:https://video-chat.exam
ple.com/;group-id=1234 ple.com/;group-id=1234
6.4. LABEL Property Parameter 6.4. LABEL Property Parameter
Parameter Name: LABEL Parameter Name: LABEL
Purpose: To provide a human readable label. Purpose: To provide a human-readable label.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
labelparam = "LABEL" "=" param-value labelparam = "LABEL" "=" param-value
Description: This property parameter MAY be specified on the Description: This property parameter MAY be specified on the
"CONFERENCE" property. It is anticipated that other extensions to "CONFERENCE" property. It is anticipated that other extensions to
iCalendar will re-use this property parameter on new properties iCalendar will reuse this property parameter on new properties
that they define. As a result, clients MUST expect to find this that they define. As a result, clients MUST expect to find this
property parameter present on many different properties. It property parameter present on many different properties. It
provides a human readable label that can be presented to calendar provides a human-readable label that can be presented to calendar
users to allow them to discriminate between properties which might users to allow them to discriminate between properties that might
be similar, or provide additional information for properties that be similar or provide additional information for properties that
are not self-describing. The "LANGUAGE" property parameter can be are not self-describing. The "LANGUAGE" property parameter can be
used to specify the language of the text in the parameter value used to specify the language of the text in the parameter value
(as per Section 3.2.10 of [RFC5545]. (as per Section 3.2.10 of [RFC5545]).
Example: Example:
CONFERENCE;VALUE=URI;FEATURE=VIDEO; CONFERENCE;VALUE=URI;FEATURE=VIDEO;
LABEL="Web video chat, access code=76543"; LABEL="Web video chat, access code=76543";
:https://video-chat.example.com/;group-id=1234 :https://video-chat.example.com/;group-id=1234
7. Security Considerations 7. Security Considerations
Several of the new properties or parameters defined by this Several of the new properties or parameters defined by this
specification allow reference to "external" URIs. Care MUST be taken specification allow reference to "external" URIs. Care MUST be taken
when accessing data at external URIs as malicious content could be when accessing data at external URIs as malicious content could be
present. Clients SHOULD ensure that suitable permission is granted present. Clients SHOULD ensure that suitable permission is granted
by calendar users before such URIs are dereferenced. by calendar users before such URIs are dereferenced.
The "REFRESH-INTERVAL" property could be used by an attacker to make The "REFRESH-INTERVAL" property could be used by an attacker to make
a client carry out rapid requests to the server hosting the calendar, a client carry out rapid requests to the server hosting the calendar
by specifying a very short duration (e.g., one second). This could by specifying a very short duration (e.g., one second). This could
lead to resource consumption on the client or server, and denial-of- lead to resource consumption on the client or server and to denial-
service attacks against the server. Clients MUST ensure that they of-service attacks against the server. Clients MUST ensure that they
throttle requests to the server to a reasonable rate. In most cases, throttle requests to the server to a reasonable rate. In most cases,
updating a public calendar once per day would suffice. If the updating a public calendar once per day would suffice. If the
"REFRESH-INTERVAL" is any less than that, clients SHOULD warn the "REFRESH-INTERVAL" is any less than that, clients SHOULD warn the
calendar user and allow them to override it with a longer value. calendar user and allow them to override it with a longer value.
The "CONFERENCE" property can include a "FEATURE" property parameter The "CONFERENCE" property can include a "FEATURE" property parameter
with a "MODERATOR" value. In some cases the access code used by the with a "MODERATOR" value. In some cases, the access code used by the
owner/initiator of a conference might be private to an individual and owner/initiator of a conference might be private to an individual,
clients and servers MUST ensure that such properties are not sent to and clients and servers MUST ensure that such properties are not sent
attendees of a scheduled component, or sharees of a shared component. to attendees of a scheduled component.
Both the "COLOR" and "IMAGE" properties are likely to be used by Both the "COLOR" and "IMAGE" properties are likely to be used by
calendar users to express their own personal view of the calendar calendar users to express their own personal view of the calendar
data. In addition, these properties could be used by attackers to data. In addition, these properties could be used by attackers to
produce a confusing display in a calendar user agent. When such produce a confusing display in a calendar user agent. When such
properties are encountered in calendar data that has come from other properties are encountered in calendar data that has come from other
calendar users (e.g., via a scheduling message, "public" calendar calendar users (e.g., via a scheduling message, "public" calendar
subscription, shared calendar etc), it is advisable for the client to subscription, etc.), it is advisable for the client to give the
give the receiving calendar user the option to remove (or adjust) receiving calendar user the option to remove (or adjust) these
these properties as the data is imported into their calendar system. properties as the data is imported into their calendar system.
This specification changes the recommendations on how "UID" property This specification changes the recommendations on how "UID" property
values are constructed to minimize leaking any information that might values are constructed to minimize leaking any information that might
be security sensitive. be security sensitive.
Security considerations in [RFC5545], and [RFC5546] MUST also be Security considerations in [RFC5545] and [RFC5546] MUST also be
adhered to. adhered to.
8. Privacy Considerations 8. Privacy Considerations
Several of the new properties or parameters defined by this Several of the new properties or parameters defined by this
specification allow reference to "external" URIs. Access to those specification allow reference to "external" URIs. Access to those
URIs could be tracked, leading to loss of privacy. Clients SHOULD URIs could be tracked, leading to loss of privacy. Clients SHOULD
ensure that suitable permission is granted by calendar users before ensure that suitable permission is granted by calendar users before
such URIs are dereferenced. In particular, calendar publishers such URIs are dereferenced. In particular, calendar publishers
wishing to help protect the privacy of their subscribers MUST use wishing to help protect the privacy of their subscribers MUST use
HTTP with Transport Layer Security [RFC7230] ("https:" URIs instead HTTP with Transport Layer Security [RFC7230] ("https:" URIs instead
of "http:" URIs) for access to calendar data or ancillary data such of "http:" URIs) for access to calendar data or ancillary data such
as images. as images.
In general, users have to rely on the privacy policies of any In general, for their own privacy protection, users have to rely on
conferencing system being accessed via the "CONFERENCE" property, for the privacy policies of any conferencing system being accessed via
their own privacy protection. It is entirely possible for such the "CONFERENCE" property. It is entirely possible for such systems
systems to uniquely identify and log the activity and participation to uniquely identify and log the activity and participation (or lack
(or not) of calendar users in the conference. Calendar user agents thereof) of calendar users in the conference. Calendar user agents
SHOULD track which conferencing systems are used and warn users the SHOULD track which conferencing systems are used and warn users the
first time a new one is about to be used. This is particularly first time a new one is about to be used. This is particularly
important if the client automatically "dials in" to the conference important if the client automatically "dials in" to the conference
when the event start time occurs. when the event start time occurs.
By giving different calendar users different values for the "REFRESH- By giving different calendar users different values for the "REFRESH-
INTERVAL" property, it is possible for a publisher of calendar data INTERVAL" property, it is possible for a publisher of calendar data
to uniquely identify each refresh from each calendar users' clients, to uniquely identify each refresh from each calendar users' clients
and thereby track user activity and IP address over time. To address and thereby track user activity and IP address over time. To address
this, clients SHOULD add or subtract some random amount of time from this, clients SHOULD add or subtract some random amount of time from
the published "REFRESH-INTERVAL" value when doing actual refreshes. the published "REFRESH-INTERVAL" value when doing actual refreshes.
This specification changes the recommendations on how "UID" property This specification changes the recommendations on how "UID" property
values are constructed to minimize leaking any information that might values are constructed to minimize leaking any information that might
be privacy sensitive. be privacy sensitive.
Privacy considerations in [RFC5545], and [RFC5546] MUST also be Privacy considerations in [RFC5545] and [RFC5546] MUST also be
adhered to. adhered to.
9. IANA Considerations 9. IANA Considerations
9.1. Property Registrations 9.1. Property Registrations
This document defines the following new iCalendar properties to be This document defines the following new iCalendar properties. IANA
added to the registry defined in Section 8.3.2 of [RFC5545]: has registered the new properties in the "Properties" registry
defined in Section 8.3.2 of [RFC5545]. IANA has also added a
reference to this document where the properties originally defined in
RFC 5545 have been updated by this document.
+------------------+---------+--------------------------------------+ +------------------+---------+--------------------------------------+
| Property | Status | Reference | | Property | Status | Reference |
+------------------+---------+--------------------------------------+ +------------------+---------+--------------------------------------+
| NAME | Current | RFCXXXX, Section 5.1 | | NAME | Current | RFC 7986, Section 5.1 |
| DESCRIPTION | Current | RFC5545 Section 3.8.1.5, RFCXXXX, | | DESCRIPTION | Current | RFC 5545, Section 3.8.1.5; RFC 7986, |
| | | Section 5.2 | | | | Section 5.2 |
| UID | Current | RFC5545 Section 3.8.4.7, RFCXXXX, | | UID | Current | RFC 5545, Section 3.8.4.7; RFC 7986, |
| | | Section 5.3 | | | | Section 5.3 |
| LAST-MODIFIED | Current | RFC5545 Section 3.8.7.3, RFCXXXX, | | LAST-MODIFIED | Current | RFC 5545, Section 3.8.7.3 RFC 7986, |
| | | Section 5.4 | | | | Section 5.4 |
| URL | Current | RFC5545 Section 3.8.4.6, RFCXXXX, | | URL | Current | RFC 5545, Section 3.8.4.6; RFC 7986, |
| | | Section 5.5 | | | | Section 5.5 |
| CATEGORIES | Current | RFC5545 Section 3.8.1.2, RFCXXXX, | | CATEGORIES | Current | RFC 5545, Section 3.8.1.2; RFC 7986, |
| | | Section 5.6 | | | | Section 5.6 |
| REFRESH-INTERVAL | Current | RFCXXXX, Section 5.7 | | REFRESH-INTERVAL | Current | RFC 7986, Section 5.7 |
| SOURCE | Current | RFCXXXX, Section 5.8 | | SOURCE | Current | RFC 7986, Section 5.8 |
| COLOR | Current | RFCXXXX, Section 5.9 | | COLOR | Current | RFC 7986, Section 5.9 |
| IMAGE | Current | RFCXXXX, Section 5.10 | | IMAGE | Current | RFC 7986, Section 5.10 |
| CONFERENCE | Current | RFCXXXX, Section 5.11 | | CONFERENCE | Current | RFC 7986, Section 5.11 |
+------------------+---------+--------------------------------------+ +------------------+---------+--------------------------------------+
9.2. Parameter Registrations 9.2. Parameter Registrations
This document defines the following new iCalendar property parameters This document defines the following new iCalendar property
to be added to the registry defined in Section 8.3.3 of [RFC5545]: parameters. IANA has registered these in the "Parameters" registry
defined in Section 8.3.3 of [RFC5545].
+--------------------+---------+----------------------+ +--------------------+---------+-----------------------+
| Property Parameter | Status | Reference | | Property Parameter | Status | Reference |
+--------------------+---------+----------------------+ +--------------------+---------+-----------------------+
| DISPLAY | Current | RFCXXXX, Section 6.1 | | DISPLAY | Current | RFC 7986, Section 6.1 |
| EMAIL | Current | RFCXXXX, Section 6.2 | | EMAIL | Current | RFC 7986, Section 6.2 |
| FEATURE | Current | RFCXXXX, Section 6.3 | | FEATURE | Current | RFC 7986, Section 6.3 |
| LABEL | Current | RFCXXXX, Section 6.4 | | LABEL | Current | RFC 7986, Section 6.4 |
+--------------------+---------+----------------------+ +--------------------+---------+-----------------------+
9.3. Property Parameter Value Registries 9.3. Property Parameter Value Registries
Two new IANA registries for iCalendar elements have been added. IANA has created two new registries for iCalendar elements: the
Additional codes MAY be used, provided the process described in "Display Types" registry and the "Feature Types" registry.
Section 8.2.1 of [RFC5545] is used to register them, using the Additional codes MAY be used, provided the process and template
template in Section 8.2.6 of [RFC5545]. described in Sections 8.2.1 and 8.2.6 of [RFC5545] are used to
register them.
9.3.1. Display Types Registry 9.3.1. Display Types Registry
The following table has been used to initialize the Display Types The following table has been used to initialize the "Display Types"
Registry. registry.
+--------------+---------+----------------------+ +--------------+---------+-----------------------+
| Display Type | Status | Reference | | Display Type | Status | Reference |
+--------------+---------+----------------------+ +--------------+---------+-----------------------+
| BADGE | Current | RFCXXXX, Section 6.1 | | BADGE | Current | RFC 7986, Section 6.1 |
| GRAPHIC | Current | RFCXXXX, Section 6.1 | | GRAPHIC | Current | RFC 7986, Section 6.1 |
| FULLSIZE | Current | RFCXXXX, Section 6.1 | | FULLSIZE | Current | RFC 7986, Section 6.1 |
| THUMBNAIL | Current | RFCXXXX, Section 6.1 | | THUMBNAIL | Current | RFC 7986, Section 6.1 |
+--------------+---------+----------------------+ +--------------+---------+-----------------------+
9.3.2. Feature Types Registry 9.3.2. Feature Types Registry
The following table has been used to initialize the Feature Types The following table has been used to initialize the "Feature Types"
Registry. registry.
+--------------+---------+----------------------+
| Feature Type | Status | Reference |
+--------------+---------+----------------------+
| AUDIO | Current | RFCXXXX, Section 6.3 |
| CHAT | Current | RFCXXXX, Section 6.3 |
| FEED | Current | RFCXXXX, Section 6.3 |
| MODERATOR | Current | RFCXXXX, Section 6.3 |
| PHONE | Current | RFCXXXX, Section 6.3 |
| SCREEN | Current | RFCXXXX, Section 6.3 |
| VIDEO | Current | RFCXXXX, Section 6.3 |
+--------------+---------+----------------------+
10. Acknowledgments
Thanks to the following for feedback: Bernard Desruisseaux, Mike
Douglass, Lucia Fedorova, Ken Murchison, Arnaud Quillaud, and Dave
Thewlis.
This specification came about via discussions at the Calendaring and +--------------+---------+-----------------------+
Scheduling Consortium. | Feature Type | Status | Reference |
+--------------+---------+-----------------------+
| AUDIO | Current | RFC 7986, Section 6.3 |
| CHAT | Current | RFC 7986, Section 6.3 |
| FEED | Current | RFC 7986, Section 6.3 |
| MODERATOR | Current | RFC 7986, Section 6.3 |
| PHONE | Current | RFC 7986, Section 6.3 |
| SCREEN | Current | RFC 7986, Section 6.3 |
| VIDEO | Current | RFC 7986, Section 6.3 |
+--------------+---------+-----------------------+
11. References 10. References
11.1. Normative References 10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally [RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally
Unique IDentifier (UUID) URN Namespace", RFC 4122, Unique IDentifier (UUID) URN Namespace", RFC 4122,
DOI 10.17487/RFC4122, July 2005, DOI 10.17487/RFC4122, July 2005,
<http://www.rfc-editor.org/info/rfc4122>. <http://www.rfc-editor.org/info/rfc4122>.
skipping to change at page 22, line 11 skipping to change at page 22, line 21
Scheduling Core Object Specification (iCalendar)", Scheduling Core Object Specification (iCalendar)",
RFC 5545, DOI 10.17487/RFC5545, September 2009, RFC 5545, DOI 10.17487/RFC5545, September 2009,
<http://www.rfc-editor.org/info/rfc5545>. <http://www.rfc-editor.org/info/rfc5545>.
[RFC5546] Daboo, C., Ed., "iCalendar Transport-Independent [RFC5546] Daboo, C., Ed., "iCalendar Transport-Independent
Interoperability Protocol (iTIP)", RFC 5546, Interoperability Protocol (iTIP)", RFC 5546,
DOI 10.17487/RFC5546, December 2009, DOI 10.17487/RFC5546, December 2009,
<http://www.rfc-editor.org/info/rfc5546>. <http://www.rfc-editor.org/info/rfc5546>.
[W3C.REC-css3-color-20110607] [W3C.REC-css3-color-20110607]
A&#135;elik, T., Lilley, C., and D. Baron, "CSS Color Celik, T., Lilley, C., and D. Baron, "CSS Color Module
Module Level 3", World Wide Web Consortium Recommendation Level 3", World Wide Web Consortium Recommendation
REC-css3-color-20110607, June 2011, REC-css3-color-20110607, June 2011,
<http://www.w3.org/TR/2011/REC-css3-color-20110607>. <https://www.w3.org/TR/2011/REC-css3-color-20110607>.
11.2. Informative References 10.2. Informative References
[RFC2397] Masinter, L., "The "data" URL scheme", RFC 2397, [RFC2397] Masinter, L., "The "data" URL scheme", RFC 2397,
DOI 10.17487/RFC2397, August 1998, DOI 10.17487/RFC2397, August 1998,
<http://www.rfc-editor.org/info/rfc2397>. <http://www.rfc-editor.org/info/rfc2397>.
[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M., and E. A., Peterson, J., Sparks, R., Handley, M., and E.
Schooler, "SIP: Session Initiation Protocol", RFC 3261, Schooler, "SIP: Session Initiation Protocol", RFC 3261,
DOI 10.17487/RFC3261, June 2002, DOI 10.17487/RFC3261, June 2002,
<http://www.rfc-editor.org/info/rfc3261>. <http://www.rfc-editor.org/info/rfc3261>.
skipping to change at page 22, line 43 skipping to change at page 23, line 5
(IRIs) and Uniform Resource Identifiers (URIs) for the (IRIs) and Uniform Resource Identifiers (URIs) for the
Extensible Messaging and Presence Protocol (XMPP)", Extensible Messaging and Presence Protocol (XMPP)",
RFC 5122, DOI 10.17487/RFC5122, February 2008, RFC 5122, DOI 10.17487/RFC5122, February 2008,
<http://www.rfc-editor.org/info/rfc5122>. <http://www.rfc-editor.org/info/rfc5122>.
[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer [RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Message Syntax and Routing", Protocol (HTTP/1.1): Message Syntax and Routing",
RFC 7230, DOI 10.17487/RFC7230, June 2014, RFC 7230, DOI 10.17487/RFC7230, June 2014,
<http://www.rfc-editor.org/info/rfc7230>. <http://www.rfc-editor.org/info/rfc7230>.
Appendix A. Change History (To be removed by RFC Editor before Acknowledgments
publication)
Changes in draft-ietf-calext-extensions-05:
1. IESG: Fixed IANA section to properly define the two new
registries.
2. IESG: Added xmpp, sip, and sips as example URIs for CONFERENCE.
3. IESG: Added languageparam to CONFERENCE and also indicated it
can appear alongside LABEL.
4. IESG: Changed SHOULD -> MUST for clients to expect LABEL.
5. IESG: Privacy: use https: instead of http:.
6. IESG: Privacy: text on tracking via CONFERENCE.
7. IESG: Privacy: text on tracking via REFRESH-INTERVAL.
8. IESG: Modified UID value generation to be stricter about what is
allowed..
9. IESG: Other editorial tweaks.
10. Removed CONFERENCE from VJOURNAL ABNF.
Changes in draft-ietf-calext-extensions-04:
1. SECDIR: Added new items to Security Considerations and added
Privacy Considerations.
2. SECDIR: fixed missing conference item in component ABNF
definitions.
3. SECDIR: editorial fixes.
Changes in draft-ietf-calext-extensions-03:
1. AD: fixed =/ ABNF syntax.
2. AD: added description for CATEGORIES.
3. AD: Removed extra / in image ABNF.
4. AD: Fixed VALUE=URI in image ABNF.
5. AD: Mention https in addition to http. Changed all examples to
use https:
6. AD: fixed DISPLAY ABNF syntax.
Changes in draft-ietf-calext-extensions-02:
1. Refresh expired draft - no changes.
Changes in draft-ietf-calext-extensions-01:
1. Clarified difference between SOURCE and URL properties.
2. Use labelparam not infoparam.
Changes in draft-ietf-calext-extensions-00:
1. Document renamed after WG adoption.
2. Fixed tel: URI reference.
Changes in draft-daboo-icalendar-extensions-09:
1. Re-instated a trimmed down version of the CONFERENCE property
after serious interest expressed by implementors.
2. LABEL property used instead of INFO - appropriated from another
iCalendar draft.
Changes in draft-daboo-icalendar-extensions-08:
1. Trimmed down the display values to a minimal set.
Changes in draft-daboo-icalendar-extensions-07:
1. Removed ALTURI parameter - now use ALTREP.
2. Removed VALID property.
3. Removed TIMEZONE-ID property.
4. Added FULLSIZE and THUMBNAIL display values.
5. Added EMAIL property parameter.
6. Added LAST-MODIFIED property for use with VCALENDAR.
7. Added CATEGORIES property for use with VCALENDAR.
8. URL use now aligned with 5545.
9. Added SOURCE property.
10. COLOR now uses CSS3 values.
Changes in draft-daboo-icalendar-extensions-06:
1. Removed BROADCAST/CONFERENCE properties and related parameters.
Changes in draft-daboo-icalendar-extensions-05:
1. Added section with recommendation on handling extension
properties.
2. Added VALID property.
Changes in draft-daboo-icalendar-extensions-04:
1. TZID changed to new property TIMEZONE-ID.
2. Minor formal syntax changes.
Changes in draft-daboo-icalendar-extensions-03:
1. Dropped CALENDAR- prefix
2. DESCRIPTION, UID and TZID now based on existing RFC5545
properties
3. COLOR now on both the calendar and component level
4. IMAGE now on both the calendar and component level
5. Added FEATURE and REGION parameters to CONFERENCE property
6. Added ALTURI parameter to IMAGE property
7. Added FEED value to FEATURE parameter
8. Added BROADCAST property and clarified that CONFERENCE is for bi-
direction channels and BROADCAST is for uni-directional.
Changes in draft-daboo-icalendar-extensions-02:
1. Minor wording changes.
2. Interval is now described as the "minimum interval".
3. Added CONFERENCE property and INFO parameter.
Changes in draft-daboo-icalendar-extensions-01:
1. Fixed DISPLAY parameter handling of x- and iana tokens to state
that clients ignore the image if the token is not recognized.
2. Allow language variants for CALENDAR-NAME and CALENDAR- Thanks to the following individuals for feedback: Bernard
DESCRIPTION. Desruisseaux, Mike Douglass, Lucia Fedorova, Ken Murchison, Arnaud
Quillaud, and Dave Thewlis.
3. Added registry for DISPLAY values. This specification came about via discussions at the Calendaring and
Scheduling Consortium.
Author's Address Author's Address
Cyrus Daboo Cyrus Daboo
Apple Inc. Apple Inc.
1 Infinite Loop 1 Infinite Loop
Cupertino, CA 95014 Cupertino, CA 95014
USA United States of America
Email: cyrus@daboo.name Email: cyrus@daboo.name
URI: http://www.apple.com/ URI: http://www.apple.com/
 End of changes. 78 change blocks. 
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