draft-ietf-calext-eventpub-extensions-11.txt   draft-ietf-calext-eventpub-extensions-12.txt 
Network Working Group M. Douglass Network Working Group M. Douglass
Internet-Draft Spherical Cow Group Internet-Draft Spherical Cow Group
Updates: 5545 (if approved) February 25, 2019 Updates: 5545 (if approved) April 8, 2019
Intended status: Standards Track Intended status: Standards Track
Expires: August 29, 2019 Expires: October 10, 2019
Event Publishing Extensions to iCalendar Event Publishing Extensions to iCalendar
draft-ietf-calext-eventpub-extensions-11 draft-ietf-calext-eventpub-extensions-12
Abstract Abstract
This specification updates RFC5545 by introducing a number of new This specification updates RFC5545 by introducing a number of new
iCalendar properties and components which are of particular use for iCalendar properties and components which are of particular use for
event publishers and in social networking. event publishers and in social networking.
This specification also defines a new STRUCTURED-DATA property for This specification also defines a new STRUCTURED-DATA property for
iCalendar RFC5545 to allow for data that is directly pertinent to an iCalendar RFC5545 to allow for data that is directly pertinent to an
event or task to be included with the calendar data. event or task to be included with the calendar data.
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 29, 2019. This Internet-Draft will expire on October 10, 2019.
Copyright Notice Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Conventions Used in This Document . . . . . . . . . . . . 4 1.1. Conventions Used in This Document . . . . . . . . . . . . 4
2. Components and properties . . . . . . . . . . . . . . . . . . 4 2. Components and properties . . . . . . . . . . . . . . . . . . 4
3. Typed References . . . . . . . . . . . . . . . . . . . . . . 5 3. Typed References . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . 5 3.1. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1.1. Piano Concert Performance . . . . . . . . . . . . . . 6 3.1.1. Piano Concert Performance . . . . . . . . . . . . . . 6
3.1.2. Itineraries . . . . . . . . . . . . . . . . . . . . . 6 3.1.2. Itineraries . . . . . . . . . . . . . . . . . . . . . 6
3.1.2.1. Reserving facilities . . . . . . . . . . . . . . 6 3.1.2.1. Reserving facilities . . . . . . . . . . . . . . 6
4. Modifications to Calendar Components . . . . . . . . . . . . 6 4. Modifications to Calendar Components . . . . . . . . . . . . 6
5. New Property Parameters . . . . . . . . . . . . . . . . . . . 7 5. New Property Parameters . . . . . . . . . . . . . . . . . . . 8
5.1. Loctype . . . . . . . . . . . . . . . . . . . . . . . . . 8 5.1. Loctype . . . . . . . . . . . . . . . . . . . . . . . . . 8
5.2. Restype . . . . . . . . . . . . . . . . . . . . . . . . . 8 5.2. Restype . . . . . . . . . . . . . . . . . . . . . . . . . 8
5.3. Order . . . . . . . . . . . . . . . . . . . . . . . . . . 9 5.3. Order . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.4. Schema . . . . . . . . . . . . . . . . . . . . . . . . . 9 5.4. Schema . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.5. Derived . . . . . . . . . . . . . . . . . . . . . . . . . 10 5.5. Derived . . . . . . . . . . . . . . . . . . . . . . . . . 10
6. Redefined Property SOURCE . . . . . . . . . . . . . . . . . . 11 6. Redefined Property SOURCE . . . . . . . . . . . . . . . . . . 11
7. New Properties . . . . . . . . . . . . . . . . . . . . . . . 12 7. New Properties . . . . . . . . . . . . . . . . . . . . . . . 12
7.1. Participant Type . . . . . . . . . . . . . . . . . . . . 12 7.1. Participant Type . . . . . . . . . . . . . . . . . . . . 12
7.2. Calendar Address . . . . . . . . . . . . . . . . . . . . 14 7.2. Calendar Address . . . . . . . . . . . . . . . . . . . . 14
7.3. Styled-Description . . . . . . . . . . . . . . . . . . . 15 7.3. Styled-Description . . . . . . . . . . . . . . . . . . . 15
7.4. Structured-Location . . . . . . . . . . . . . . . . . . . 17 7.4. Structured-Location . . . . . . . . . . . . . . . . . . . 17
7.5. Structured-Resource . . . . . . . . . . . . . . . . . . . 18 7.5. Structured-Resource . . . . . . . . . . . . . . . . . . . 18
7.6. Structured-Data . . . . . . . . . . . . . . . . . . . . . 20 7.6. Structured-Data . . . . . . . . . . . . . . . . . . . . . 20
8. New Components . . . . . . . . . . . . . . . . . . . . . . . 22 8. New Components . . . . . . . . . . . . . . . . . . . . . . . 22
8.1. Participant . . . . . . . . . . . . . . . . . . . . . . . 23 8.1. Participant . . . . . . . . . . . . . . . . . . . . . . . 23
8.2. Schedulable Participant . . . . . . . . . . . . . . . . . 25 8.2. Schedulable Participant . . . . . . . . . . . . . . . . . 25
9. Extended examples . . . . . . . . . . . . . . . . . . . . . . 25 9. Extended examples . . . . . . . . . . . . . . . . . . . . . . 26
9.1. Example 1 . . . . . . . . . . . . . . . . . . . . . . . . 25 9.1. Example 1 . . . . . . . . . . . . . . . . . . . . . . . . 26
9.2. Example 2 . . . . . . . . . . . . . . . . . . . . . . . . 26 9.2. Example 2 . . . . . . . . . . . . . . . . . . . . . . . . 26
10. Security Considerations . . . . . . . . . . . . . . . . . . . 27 10. Security Considerations . . . . . . . . . . . . . . . . . . . 27
11. Privacy Considerations . . . . . . . . . . . . . . . . . . . 27 11. Privacy Considerations . . . . . . . . . . . . . . . . . . . 27
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 27 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 28
12.1. Additional iCalendar Registrations . . . . . . . . . . . 28 12.1. Additional iCalendar Registrations . . . . . . . . . . . 28
12.1.1. Properties . . . . . . . . . . . . . . . . . . . . . 28 12.1.1. Properties . . . . . . . . . . . . . . . . . . . . . 28
12.1.2. Parameters . . . . . . . . . . . . . . . . . . . . . 28 12.1.2. Parameters . . . . . . . . . . . . . . . . . . . . . 28
12.1.3. Components . . . . . . . . . . . . . . . . . . . . . 28 12.1.3. Components . . . . . . . . . . . . . . . . . . . . . 28
12.2. New Registration Tables . . . . . . . . . . . . . . . . 29 12.2. New Registration Tables . . . . . . . . . . . . . . . . 29
12.2.1. Participant Types . . . . . . . . . . . . . . . . . 29 12.2.1. Participant Types . . . . . . . . . . . . . . . . . 29
12.2.2. Resource Types . . . . . . . . . . . . . . . . . . . 29 12.2.2. Resource Types . . . . . . . . . . . . . . . . . . . 29
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 29 13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 29
14. References . . . . . . . . . . . . . . . . . . . . . . . . . 30 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 30
14.1. Normative References . . . . . . . . . . . . . . . . . . 30 14.1. Normative References . . . . . . . . . . . . . . . . . . 30
14.2. Informative References . . . . . . . . . . . . . . . . . 30 14.2. Informative References . . . . . . . . . . . . . . . . . 31
Appendix A. Open issues . . . . . . . . . . . . . . . . . . . . 31 Appendix A. Open issues . . . . . . . . . . . . . . . . . . . . 31
Appendix B. Change log . . . . . . . . . . . . . . . . . . . . . 31 Appendix B. Change log . . . . . . . . . . . . . . . . . . . . . 31
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 33 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 34
1. Introduction 1. Introduction
The currently existing iCalendar standard [RFC5545] lacks useful The currently existing iCalendar standard [RFC5545] lacks useful
methods for referencing additional, external information relating to methods for referencing additional, external information relating to
calendar components. Additionally there is no standard way to calendar components. Additionally there is no standard way to
provide rich text descriptions or meta-data associated with the provide rich text descriptions or meta-data associated with the
event. event.
Current practice is to embed this information as links in the Current practice is to embed this information as links in the
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2. Components and properties 2. Components and properties
Previous extensions to the calendaring standards have been largely Previous extensions to the calendaring standards have been largely
restricted to the addition of properties or parameters. This is restricted to the addition of properties or parameters. This is
partly because iCalendar libraries had trouble handling components partly because iCalendar libraries had trouble handling components
nested deeper than those defined in [RFC5545] nested deeper than those defined in [RFC5545]
In a break with this 'tradition' this specification introduces one of In a break with this 'tradition' this specification introduces one of
these extensions as a component rather than a property. This is a these extensions as a component rather than a property. This is a
better match for the way XML and JSON handles such structures and better match for the way [W3C.REC-xml-20081126] and JSON, [RFC8259]
allows richer definitions. handles such structures and allows richer definitions.
It also allows for the addition of extra properties inside the It also allows for the addition of extra properties inside the
component and resolves some of the problems of trying to add detailed component and resolves some of the problems of trying to add detailed
information as a parameter. information as a parameter.
3. Typed References 3. Typed References
The properties defined here can all reference external meta-data The properties defined here can all reference external meta-data
which may be used by applications to provide enhanced value to users. which may be used by applications to provide enhanced value to users.
By providing type information as parameters, clients and servers are By providing type information as parameters, clients and servers are
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The PARTICIPANT component is designed to handle common use cases in The PARTICIPANT component is designed to handle common use cases in
event publication. It is generally important to provide information event publication. It is generally important to provide information
about the organizers of such events. Sponsors wish to be referenced about the organizers of such events. Sponsors wish to be referenced
in a prominent manner. In social calendaring it is often important in a prominent manner. In social calendaring it is often important
to identify the active participants in the event, for example a to identify the active participants in the event, for example a
school sports team, and the inactive participants, for example the school sports team, and the inactive participants, for example the
parents. parents.
The PARTICIPANT component can also be used to provide useful extra The PARTICIPANT component can also be used to provide useful extra
data about an attendee. For example a LOCATION property inside the data about an attendee. For example a LOCATION property inside the
PARTICIPANT gives the actual location of a remote attendee. PARTICIPANT gives the actual location of a remote attendee. (But see
the note about privacy.)
3.1. Use Cases 3.1. Use Cases
The main motivation for these properties has been event publication The main motivation for these properties has been event publication
but there are opportunities for use elsewhere. The following use but there are opportunities for use elsewhere. The following use
cases will describe some possible scenarios. cases will describe some possible scenarios.
3.1.1. Piano Concert Performance 3.1.1. Piano Concert Performance
In putting together a concert there are many participants: piano In putting together a concert there are many participants: piano
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airport or to their final destination. The contact information can airport or to their final destination. The contact information can
provide detailed information about the booking agent, the airlines, provide detailed information about the booking agent, the airlines,
car hire companies and the hotel. car hire companies and the hotel.
3.1.2.1. Reserving facilities 3.1.2.1. Reserving facilities
For a meeting, the size of a room and the equipment needed depends to For a meeting, the size of a room and the equipment needed depends to
some extent on the number of attendees actually in the room. some extent on the number of attendees actually in the room.
A meeting may have 10 attendees non of which are co-located. The A meeting may have 10 attendees non of which are co-located. The
current ATTENDEE property dos not allow for the additon of such meta- current ATTENDEE property does not allow for the addition of such
data. The PARTICIPANT property allows attendees to specify their meta-data. The PARTICIPANT property allows attendees to specify
location. their location.
4. Modifications to Calendar Components 4. Modifications to Calendar Components
The following changes to the syntax defined in iCalendar [RFC5545] The following changes to the syntax defined in iCalendar [RFC5545]
are made here. New elements are defined in subsequent sections. are made here. New elements are defined in subsequent sections.
eventc = "BEGIN" ":" "VEVENT" CRLF eventc = "BEGIN" ":" "VEVENT" CRLF
eventprop *alarmc *participantc eventprop *alarmc *participantc
"END" ":" "VEVENT" CRLF "END" ":" "VEVENT" CRLF
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jourprop =/ *( jourprop =/ *(
; ;
; The following are OPTIONAL, ; The following are OPTIONAL,
; and MAY occur more than once. ; and MAY occur more than once.
; ;
styleddescription / sdataprop styleddescription / sdataprop
; ;
) )
freebusyc = "BEGIN" ":" "VFREEBUSY" CRLF
fbprop *participantc
"END" ":" "VFREEBUSY" CRLF
5. New Property Parameters 5. New Property Parameters
This specification makes use of the LABEL parameter which is defined This specification makes use of the LABEL parameter which is defined
in [RFC7986] in [RFC7986]
5.1. Loctype 5.1. Loctype
Parameter name: LOCTYPE Parameter name: LOCTYPE
Purpose: To specify the type of location. Purpose: To specify the type of location.
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properties. When present with a value of TRUE clients MUST NOT properties. When present with a value of TRUE clients MUST NOT
update the property. update the property.
As an example, if a STYLED-DESCRIPTION property is present with As an example, if a STYLED-DESCRIPTION property is present with
FMTTYPE="application/rtf" then there may be an additional STYLED- FMTTYPE="application/rtf" then there may be an additional STYLED-
DESCRIPTION property with FMTTYPE="text/html" and DERIVED=TRUE and DESCRIPTION property with FMTTYPE="text/html" and DERIVED=TRUE and
a value created from the rtf value. a value created from the rtf value.
Example: Example:
STRUCTURED-DESCRIPTION;FMTTYPE=text/html; STYLED-DESCRIPTION;FMTTYPE=text/html;
DERIVED=TRUE:<html>... DERIVED=TRUE:<html>...
6. Redefined Property SOURCE 6. Redefined Property SOURCE
The SOURCE property defined in [RFC7986] is redefined to allow The SOURCE property defined in [RFC7986] is redefined to allow
VALUE=TEXT and broaden its usage to any component. VALUE=TEXT and broaden its usage to any component.
Property name: SOURCE Property name: SOURCE
Purpose: This property provides a reference to information about a Purpose: This property provides a reference to information about a
component such as a participant possibly as a vcard or optionally component such as a participant possibly as a vcard or optionally
a plain text typed value. a plain text typed value.
Value type: The default value type for this property is URI. The Value type: The default value type for this property is URI. The
value type can also be set to TEXT to indicate plain text content. value type can also be set to TEXT to indicate plain text content.
Property Parameters: Non-standard or format type parameters can be Property Parameters: Non-standard or format type parameters can be
specified on this property. specified on this property.
Conformance: This property MAY be appear in any iCalendar component. Conformance: This property MAY appear in any iCalendar component.
Description: This property provides information about the component Description: This property provides information about the component
in which it appears. in which it appears.
In a resource or participant it may provide a reference to a vcard In a resource or participant it may provide a reference to a vcard
giving directory information. giving directory information.
In a VCALENDAR component this property identifies a location where In a VCALENDAR component this property identifies a location where
a client can retrieve updated data for the calendar. Clients a client can retrieve updated data for the calendar. Clients
SHOULD honor any specified "REFRESH-INTERVAL" value when SHOULD honor any specified "REFRESH-INTERVAL" value when
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VALUE=URI is used to provide a link to rich-text content which is VALUE=URI is used to provide a link to rich-text content which is
expected to be displayed inline as part of the event. expected to be displayed inline as part of the event.
In either case the DESCRIPTION property should be absent or In either case the DESCRIPTION property should be absent or
contain a plain text rendering of the styled text. contain a plain text rendering of the styled text.
Applications MAY attempt to guess the media type of the resource Applications MAY attempt to guess the media type of the resource
via inspection of its content if and only if the media type of the via inspection of its content if and only if the media type of the
resource is not given by the "FMTTYPE" parameter. If the media resource is not given by the "FMTTYPE" parameter. If the media
type remains unknown, calendar applications SHOULD treat it as type remains unknown, calendar applications SHOULD treat it as
type "text/html". type "text/html" and process the content as defined in
[W3C.REC-html51-20171003]
Multiple STYLED-DESCRIPTION properties may be used to provide Multiple STYLED-DESCRIPTION properties may be used to provide
different formats or different language variants. However all but different formats or different language variants. However all but
one MUST have DERIVED=TRUE. one MUST have DERIVED=TRUE.
Format Definition: Format Definition:
This property is defined by the following notation: This property is defined by the following notation:
styleddescription = "STYLED-DESCRIPTION" styleddescparam ":" styleddescription = "STYLED-DESCRIPTION" styleddescparam ":"
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"homeTeam": "Pittsburgh Pirates"\,\n "homeTeam": "Pittsburgh Pirates"\,\n
"awayTeam": "San Francisco Giants"\n "awayTeam": "San Francisco Giants"\n
}\n }\n
8. New Components 8. New Components
8.1. Participant 8.1. Participant
Component name: PARTICIPANT Component name: PARTICIPANT
Purpose: This component provides information about a participant in Purpose: This component provides information about a participant in
an event or optionally a plain text typed value. an event or task.
Conformance: This component MAY be appear in any iCalendar Conformance: This component MAY appear in any iCalendar component.
component.
Description: This component provides information about an Description: This component provides information about an
participant in an event, task or poll. A participant may be an participant in an event, task or poll. A participant may be an
attendee in a scheduling sense and the ATTENDEE property may be attendee in a scheduling sense and the ATTENDEE property may be
specified in addition. Participants in events can be individuals specified in addition. Participants in events can be individuals
or organizations, for example a soccer team, the spectators, or or organizations, for example a soccer team, the spectators, or
the musicians. the musicians.
The SOURCE property if present may refer to an external definition The SOURCE property if present may refer to an external definition
of the participant - such as a vcard. of the participant - such as a vcard.
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address. If an ATTENDEE property has the same value the address. If an ATTENDEE property has the same value the
participant is considered schedulable. The PARTICIPANT component participant is considered schedulable. The PARTICIPANT component
can be used to contain additional meta-data related to the can be used to contain additional meta-data related to the
attendee. attendee.
Format Definition: Format Definition:
This property is defined by the following notation: This property is defined by the following notation:
participantc = "BEGIN" ":" "PARTICIPANT" CRLF participantc = "BEGIN" ":" "PARTICIPANT" CRLF
partprop *alarmc partprop
"END" ":" "PARTICIPANT" CRLF "END" ":" "PARTICIPANT" CRLF
partprop = *( partprop = *(
; ;
; The following are REQUIRED, ; The following are REQUIRED,
; but MUST NOT occur more than once. ; but MUST NOT occur more than once.
; ;
dtstamp / participanttype / dtstamp / participanttype /
; ;
; The following are OPTIONAL, ; The following are OPTIONAL,
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attach / categories / comment / attach / categories / comment /
contact / location / rstatus / related / contact / location / rstatus / related /
resources / strucloc / strucres / styleddescription / resources / strucloc / strucres / styleddescription /
x-prop / iana-prop x-prop / iana-prop
; ;
) )
Note: When the PRIORITY is supplied it defines the ordering of Note: When the PRIORITY is supplied it defines the ordering of
PARTICIPANT components with the same value for the TYPE parameter. PARTICIPANT components with the same value for the TYPE parameter.
Privacy Issues: When a LOCATION is supplied it provides information
about the location of a participant at a given time or times.
This may represent an unacceptable privacy risk for some
participants. User agents MUST NOT include this information
without informing the participant.
Example: Example:
The following is an example of this component. It contains a SOURCE The following is an example of this component. It contains a SOURCE
property which points to a VCARD providing information about the property which points to a VCARD providing information about the
event participant. event participant.
BEGIN:PARTICIPANT BEGIN:PARTICIPANT
PARTICIPANT-TYPE:PRINCIPAL_PERFORMER PARTICIPANT-TYPE:PERFORMER
SOURCE:http://dir.example.com/vcard/aviolinist.vcf SOURCE:http://dir.example.com/vcard/aviolinist.vcf
END:PARTICIPANT END:PARTICIPANT
Example: Example:
The following is an example for the primary contact. The following is an example for the primary contact.
BEGIN: PARTICIPANT BEGIN: PARTICIPANT
SOURCE;FMTTYPE=text/vcard; SOURCE;FMTTYPE=text/vcard;
http://dir.example.com/vcard/contacts/contact1.vcf http://dir.example.com/vcard/contacts/contact1.vcf
PARTICIPANT-TYPE:PRIMARY-CONTACT PARTICIPANT-TYPE:CONTACT
DESCRIPTION:A contact: DESCRIPTION:A contact:
END:PARTICIPANT END:PARTICIPANT
8.2. Schedulable Participant 8.2. Schedulable Participant
A PARTICIPANT component may represent someone or something that needs A PARTICIPANT component may represent someone or something that needs
to be scheduled as defined for ATTENDEE in [RFC5545] and [RFC5546]. to be scheduled as defined for ATTENDEE in [RFC5545] and [RFC5546].
The PARTICIPANT component may also represent someone or something The PARTICIPANT component may also represent someone or something
that is NOT to receive scheduling messages. that is NOT to receive scheduling messages.
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10. Security Considerations 10. Security Considerations
Applications using these properties need to be aware of the risks Applications using these properties need to be aware of the risks
entailed in using the URIs provided as values. See [RFC3986] for a entailed in using the URIs provided as values. See [RFC3986] for a
discussion of the security considerations relating to URIs. discussion of the security considerations relating to URIs.
Security considerations relating to the "ATTACH" property, as Security considerations relating to the "ATTACH" property, as
described in [RFC5545], are applicable to the "STRUCTURED-DATA" described in [RFC5545], are applicable to the "STRUCTURED-DATA"
property. property.
When processing HTML content applications need to be aware of the
many security and privacy issues as described in the IANA
considerations section of [W3C.REC-html51-20171003]
11. Privacy Considerations 11. Privacy Considerations
Properties with a "URI" value type can expose their users to privacy Properties with a "URI" value type can expose their users to privacy
leaks as any network access of the URI data can be tracked. Clients leaks as any network access of the URI data can be tracked. Clients
SHOULD NOT automatically download data referenced by the URI without SHOULD NOT automatically download data referenced by the URI without
explicit instruction from users. This specification does not explicit instruction from users. This specification does not
introduce any additional privacy concerns beyond those described in introduce any additional privacy concerns beyond those described in
[RFC5545]. [RFC5545].
The addition of location information to the new participant component
provides information about the location of participants at a given
time.
12. IANA Considerations 12. IANA Considerations
This section defines updates to the tables defined in [RFC5545] and This section defines updates to the tables defined in [RFC5545] and
new tables. new tables.
12.1. Additional iCalendar Registrations 12.1. Additional iCalendar Registrations
12.1.1. Properties 12.1.1. Properties
This document defines the following new iCalendar properties to be This document defines the following new iCalendar properties to be
skipping to change at page 30, line 45 skipping to change at page 30, line 45
<https://www.rfc-editor.org/info/rfc5546>. <https://www.rfc-editor.org/info/rfc5546>.
[RFC7986] Daboo, C., "New Properties for iCalendar", RFC 7986, [RFC7986] Daboo, C., "New Properties for iCalendar", RFC 7986,
DOI 10.17487/RFC7986, October 2016, DOI 10.17487/RFC7986, October 2016,
<https://www.rfc-editor.org/info/rfc7986>. <https://www.rfc-editor.org/info/rfc7986>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8259] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
Interchange Format", STD 90, RFC 8259,
DOI 10.17487/RFC8259, December 2017,
<https://www.rfc-editor.org/info/rfc8259>.
[W3C.REC-html51-20171003]
Faulkner, S., Eicholz, A., Leithead, T., and A. Danilo,
"HTML 5.1 2nd Edition", World Wide Web Consortium
Recommendation REC-html51-20171003, October 2017,
<https://www.w3.org/TR/2017/REC-html51-20171003>.
[W3C.REC-xml-20081126]
Bray, T., Paoli, J., Sperberg-McQueen, M., Maler, E., and
F. Yergeau, "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>.
14.2. Informative References 14.2. Informative References
[iana-property-registry] [iana-property-registry]
"IANA iCalendar Element Registries", "IANA iCalendar Element Registries",
<https://www.iana.org/assignments/icalendar/ <https://www.iana.org/assignments/icalendar/
icalendar.xhtml>. icalendar.xhtml>.
Appendix A. Open issues Appendix A. Open issues
None at the moment None at the moment
Appendix B. Change log Appendix B. Change log
calext-v12 2019-02-28 MD
o Fix styled-description example. Respond to various AD issues.
Some typos.
calext-v11 2019-02-27 MD
o Add DERIVED parameter for styled-description, RELATED parameter
for structured-location
calext-v09 2018-08-30 MD calext-v09 2018-08-30 MD
o Sorted out inconsistencies in refs to 5546 o Sorted out inconsistencies in refs to 5546
calext-v08 2018-07-06 MD calext-v08 2018-07-06 MD
o Add some text for equal ORDER values o Add some text for equal ORDER values
o Switched scheduleaddress to calendaraddress in participant abnf. o Switched scheduleaddress to calendaraddress in participant abnf.
Also added more properties Also added more properties
 End of changes. 27 change blocks. 
26 lines changed or deleted 73 lines changed or added

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