rfc9073.original   rfc9073.txt 
Network Working Group M. Douglass Internet Engineering Task Force (IETF) M. Douglass
Internet-Draft Bedework Request for Comments: 9073 Bedework
Updates: 5545 (if approved) January 13, 2021 Updates: 5545 July 2021
Intended status: Standards Track Category: Standards Track
Expires: July 17, 2021 ISSN: 2070-1721
Event Publishing Extensions to iCalendar Event Publishing Extensions to iCalendar
draft-ietf-calext-eventpub-extensions-18
Abstract Abstract
This specification updates RFC5545 by introducing a number of new This specification updates RFC 5545 by introducing a number of new
iCalendar properties and components which are of particular use for iCalendar properties and components that 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 (RFC 5545) to allow for data that is directly pertinent to
event or task to be included with the calendar data. an event or task to be included with the calendar data.
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
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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 July 17, 2021. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9073.
Copyright Notice Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction
1.1. Conventions Used in This Document . . . . . . . . . . . . 3 1.1. Conventions Used in This Document
1.2. Terms Used in This Document . . . . . . . . . . . . . . . 3 1.2. Terms Used in This Document
2. Components and properties . . . . . . . . . . . . . . . . . . 4 2. Components and Properties
3. Typed References . . . . . . . . . . . . . . . . . . . . . . 4 3. Typed References
3.1. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . 5 3.1. Use Cases
3.1.1. Piano Concert Performance . . . . . . . . . . . . . . 5 3.1.1. Piano Concert Performance
3.1.2. Itineraries . . . . . . . . . . . . . . . . . . . . . 5 3.1.2. Itineraries
3.1.2.1. Reserving facilities . . . . . . . . . . . . . . 6 3.1.2.1. Reserving Facilities
4. Modifications to Calendar Components . . . . . . . . . . . . 6 4. Modifications to Calendar Components
5. New Property Parameters . . . . . . . . . . . . . . . . . . . 7 5. New Property Parameters
5.1. Order . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5.1. Order
5.2. Schema . . . . . . . . . . . . . . . . . . . . . . . . . 8 5.2. Schema
5.3. Derived . . . . . . . . . . . . . . . . . . . . . . . . . 9 5.3. Derived
6. New Properties . . . . . . . . . . . . . . . . . . . . . . . 10 6. New Properties
6.1. Location Type . . . . . . . . . . . . . . . . . . . . . . 10 6.1. Location Type
6.2. Participant Type . . . . . . . . . . . . . . . . . . . . 11 6.2. Participant Type
6.3. Resource Type . . . . . . . . . . . . . . . . . . . . . . 13 6.3. Resource Type
6.4. Calendar Address . . . . . . . . . . . . . . . . . . . . 14 6.4. Calendar Address
6.5. Styled-Description . . . . . . . . . . . . . . . . . . . 14 6.5. Styled-Description
6.6. Structured-Data . . . . . . . . . . . . . . . . . . . . . 16 6.6. Structured-Data
7. New Components . . . . . . . . . . . . . . . . . . . . . . . 18 7. New Components
7.1. Participant . . . . . . . . . . . . . . . . . . . . . . . 18 7.1. Participant
7.1.1. Schedulable Participant . . . . . . . . . . . . . . . 22 7.1.1. Schedulable Participant
7.2. Location . . . . . . . . . . . . . . . . . . . . . . . . 22 7.2. Location
7.3. Resource . . . . . . . . . . . . . . . . . . . . . . . . 23 7.3. Resource
8. Extended examples . . . . . . . . . . . . . . . . . . . . . . 25 8. Extended Examples
8.1. Example 1 . . . . . . . . . . . . . . . . . . . . . . . . 25 8.1. Example 1
8.2. Example 2 . . . . . . . . . . . . . . . . . . . . . . . . 26 8.2. Example 2
9. Security Considerations . . . . . . . . . . . . . . . . . . . 27 9. Security Considerations
9.1. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 27 9.1. URIs
9.2. Malicious Content . . . . . . . . . . . . . . . . . . . . 28 9.2. Malicious Content
9.3. HTML Content . . . . . . . . . . . . . . . . . . . . . . 28 9.3. HTML Content
10. Privacy Considerations . . . . . . . . . . . . . . . . . . . 28 10. Privacy Considerations
10.1. Tracking . . . . . . . . . . . . . . . . . . . . . . . . 28 10.1. Tracking
10.2. Revealing Locations . . . . . . . . . . . . . . . . . . 28 10.2. Revealing Locations
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 29 11. IANA Considerations
11.1. Additional iCalendar Registrations . . . . . . . . . . . 29 11.1. Additional iCalendar Registrations
11.1.1. Properties . . . . . . . . . . . . . . . . . . . . . 29 11.1.1. Properties
11.1.2. Parameters . . . . . . . . . . . . . . . . . . . . . 29 11.1.2. Parameters
11.1.3. Components . . . . . . . . . . . . . . . . . . . . . 30 11.1.3. Components
11.2. New Registration Tables . . . . . . . . . . . . . . . . 30 11.2. Participant Types and Resource Types Registries
11.2.1. Participant Types . . . . . . . . . . . . . . . . . 30 11.2.1. Participant Types
11.2.2. Resource Types . . . . . . . . . . . . . . . . . . . 31 11.2.2. Resource Types
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 31 12. Normative References
13. Normative References . . . . . . . . . . . . . . . . . . . . 31 Acknowledgements
Appendix A. Open issues . . . . . . . . . . . . . . . . . . . . 33 Author's Address
Appendix B. Change log . . . . . . . . . . . . . . . . . . . . . 33
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 36
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 metadata 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
description or to add non-standard properties as defined in [RFC5545] description or to add nonstandard properties, as defined in
section 3.8.8.2. Section 3.8.8.2 of [RFC5545].
This document updates [RFC5545] to define a number of properties and This document updates [RFC5545] to define a number of properties and
components referencing such external information that can provide components referencing such external information that can provide
additional information about an iCalendar component. The intent is additional information about an iCalendar component. The intent is
to allow interchange of such information between applications or to allow the interchange of such information between applications or
systems (e.g., between clients, between client and server, and systems (e.g., between clients, between client and server, and
between servers). Formats such as vCard [RFC2426] are likely to be between servers). Formats, such as vCard [RFC6350], are likely to be
most useful to the receivers of such events as they may be used in most useful to the receivers of such events as they may be used in
other applications - such as address books. other applications -- such as address books.
1.1. Conventions Used in This Document 1.1. 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 BCP "OPTIONAL" in this document are to be interpreted as described in
14 [RFC2119] [RFC8174] when, and only when, they appear in all BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
The notation used in this memo is the ABNF notation of [RFC5234] as
used by iCalendar [RFC5545]. Any syntax elements shown below that
are not explicitly defined in this specification come from iCalendar
[RFC5545].
1.2. Terms Used in This Document 1.2. Terms Used in This Document
Event: When the (perhaps with a capitalised 'E') word 'event' is Event: When the word 'event' (perhaps with a capitalized 'E') is
used we are referring to gatherings, formal or informal. For used, we are referring to gatherings, formal or informal (for
example a sports event, a party or a concert. example, a sports event, a party, or a concert).
Social Calendaring: Historically, calendar data and scheduling has Social Calendaring: Historically, calendar data and scheduling has
been heavily biased towards meetings in a corporate environment. been heavily biased towards meetings in a corporate environment.
Some of the features defined in this document are to support a Some of the features defined in this document are to support a
more informal, i.e. social, model. For example, we may want to more informal, i.e., social, model. For example, we may want to
record who is participating in a public event. record who is participating in a public event.
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 defines a number In a break with this 'convention', this specification defines a
of components rather than properties. This is a better match for the number of components rather than properties. This is a better match
way [W3C.REC-xml-20081126] and JSON [RFC8259] handle such structures for the way [W3C.REC-xml-20081126] and JSON [RFC8259] handle such
and allows richer definitions. 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
components and resolves some of the problems of trying to add components and resolves some of the problems of trying to add
detailed information as a parameter. detailed information as a parameter.
3. Typed References 3. Typed References
The properties and components defined here can all reference external The properties and components defined here can all reference external
meta-data which may be used by applications to provide further metadata, which may be used by applications to provide further
information to users. By providing type information, clients and information to users. By providing type information, clients and
servers are able to discover interesting references and make use of servers are able to discover interesting references and make use of
them, perhaps for indexing or the presenting of additional related them, perhaps for indexing or presenting additional, related
information for the user. information for the user.
As always, clients should exercise caution in following references to As always, clients should exercise caution in following references to
external data. external data.
The [RFC5545] LOCATION property provides only an unstructured single The "LOCATION" property [RFC5545] provides only an unstructured
text value for specifying the location where an event (or task) will single text value for specifying the location where an event (or
occur. This is inadequate for use cases where structured location task) will occur. This is inadequate for use cases where structured
information (e.g. address, region, country, postal code) is required location information (e.g., address, region, country, or postal code)
or preferred, and limits widespread adoption of iCalendar in those is required or preferred and limits widespread adoption of iCalendar
settings. in those settings.
Using the VLOCATION component, rich information about multiple Using the "VLOCATION" component, rich information about multiple
locations can be communicated in a STRUCTURED-DATA property, for locations can be communicated in a "STRUCTURED-DATA" property;
example, address, region, country, postal code as well as other examples include address, region, country, postal code, parking
information such as parking availability, nearby restaurants and the availability, nearby restaurants, and the venue, among others.
venue. Servers and clients can retrieve the objects when storing the Servers and clients can retrieve the objects when storing the event
event and use them to index by geographic location. and use them to index by geographic location.
When a calendar client receives a calendar component it can search When a calendar client receives a calendar component, it can search
the set of locations looking for those of particular interest. The the set of locations looking for those of particular interest. The
LOCATION-TYPE property and STRUCTURED-DATA FMTTYPE parameter, if "LOCATION-TYPE" property and "FMTTYPE" parameter applied to the
supplied, can be used to help the selection. "STRUCTURED-DATA" property, if supplied, can be used to help the
selection.
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 (e.g,, a school sports team) and
school sports team, and the inactive participants, for example the the inactive participants (e.g., the parents) in the event.
parents.
The PARTICIPANT component can be used to provide useful extra data The "PARTICIPANT" component can be used to provide useful extra data
about an attendee. For example a location inside the PARTICIPANT about an attendee. For example, a location inside the PARTICIPANT
gives the actual location of a remote attendee. (But see the note gives the actual location of a remote attendee. (But see the note
about privacy.) about privacy.)
Alternatively the PARTICIPANT component can be used to provide a Alternatively, the "PARTICIPANT" component can be used to provide a
reference - perhaps the address for mailing lists. reference -- perhaps the address for mailing lists.
3.1. Use Cases 3.1. Use Cases
The main motivation for these changes has been event publication but The main motivation for these changes has been event publication, but
there are opportunities for use elsewhere. The following use cases there are opportunities for use elsewhere. The following use cases
will describe some possible scenarios. 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
tuner, performer, stage hands etc. In addition there are sponsors tuner, performer, stage hands, etc. In addition, there are sponsors
and various contacts to be provided. There will also be a number of and various contacts to be provided. There will also be a number of
related locations. A number of events can be created, all of which related locations. A number of events can be created, all of which
relate to the performance in different ways. relate to the performance in different ways.
There may be an iTip [RFC5546] meeting request for the piano tuner There may be an iCalendar Transport-independent Interoperability
who will arrive before the performance. Other members of staff may Protocol (iTIP) [RFC5546] meeting request for the piano tuner, who
also receive meeting requests. will arrive before the performance. Other members of staff may also
receive meeting requests.
An event can also be created for publication which will have a An event can also be created for publication, which will have a
PARTICIPANT component for the pianist providing a reference to vCard "PARTICIPANT" component for the pianist providing a reference to
[RFC2426] information about the performer. This event would also vCard information ([RFC6350]) about the performer. This event would
hold information about parking, local subway stations and the venue also hold information about parking, local subway stations, and the
itself. In addition, there may be sponsorship information for venue itself. In addition, there may be sponsorship information for
sponsors of the event and perhaps paid sponsorship properties sponsors of the event and perhaps paid sponsorship properties,
essentially advertising local establishments. essentially advertising local establishments.
3.1.2. Itineraries 3.1.2. Itineraries
These additions also provide opportunities for the travel industry. These additions also provide opportunities for the travel industry.
When booking a flight the PARTICIPANT component can be used to When booking a flight, the "PARTICIPANT" component can be used to
provide references to businesses at the airports and to car hire provide references to businesses at the airports and to rental car
businesses at the destination. businesses at the destination.
The embedded location information can guide the traveler at the The embedded location information can guide the traveler around the
airport or to their final destination. The contact information can airport itself or to their final destination. The contact
provide detailed information about the booking agent, the airlines, information can provide detailed information about the booking agent,
car hire companies and the hotel. airlines, car hire companies, and 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,
some extent on the number of attendees actually in the room. to some extent, on the number of attendees actually in the room.
A meeting may have many attendees none of which are co-located. The A meeting may have many attendees, none of which are co-located. The
current ATTENDEE property does not allow for the addition of such current "ATTENDEE" property does not allow for the addition of such
meta-data. The PARTICIPANT component allows attendees to specify metadata. The "PARTICIPANT" component allows attendees to specify
their 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.
; Addition of PARTICIPANT, VLOCATION and VRESOURCE ; Addition of PARTICIPANT, VLOCATION, and VRESOURCE
; as valid components ; as valid components
eventc = "BEGIN" ":" "VEVENT" CRLF eventc = "BEGIN" ":" "VEVENT" CRLF
eventprop *alarmc *participantc *locationc *resourcec eventprop *alarmc *participantc *locationc *resourcec
"END" ":" "VEVENT" CRLF "END" ":" "VEVENT" CRLF
; Addition of properties STYLED-DESCRIPTION and STRUCTURED-DATA ; Addition of properties STYLED-DESCRIPTION and STRUCTURED-DATA
eventprop =/ *styleddescription eventprop =/ *styleddescription
*sdataprop *sdataprop
; Addition of PARTICIPANT, VLOCATION and VRESOURCE ; Addition of PARTICIPANT, VLOCATION, and VRESOURCE
; as valid components ; as valid components
todoc = "BEGIN" ":" "VTODO" CRLF todoc = "BEGIN" ":" "VTODO" CRLF
todoprop *alarmc *participantc *locationc *resourcec todoprop *alarmc *participantc *locationc *resourcec
"END" ":" "VTODO" CRLF "END" ":" "VTODO" CRLF
; Addition of properties STYLED-DESCRIPTION, STRUCTURED-DATA ; Addition of properties STYLED-DESCRIPTION and STRUCTURED-DATA
todoprop =/ *styleddescription todoprop =/ *styleddescription
*sdataprop *sdataprop
; Addition of PARTICIPANT, VLOCATION and VRESOURCE ; Addition of PARTICIPANT, VLOCATION, and VRESOURCE
; as valid components ; as valid components
journalc = "BEGIN" ":" "VJOURNAL" CRLF journalc = "BEGIN" ":" "VJOURNAL" CRLF
jourprop *participantc *locationc *resourcec jourprop *participantc *locationc *resourcec
"END" ":" "VJOURNAL" CRLF "END" ":" "VJOURNAL" CRLF
; Addition of properties STYLED-DESCRIPTION, STRUCTURED-DATA ; Addition of properties STYLED-DESCRIPTION and STRUCTURED-DATA
jourprop =/ *styleddescription jourprop =/ *styleddescription
*sdataprop *sdataprop
; Addition of PARTICIPANT, VLOCATION and VRESOURCE ; Addition of PARTICIPANT, VLOCATION, and VRESOURCE
; as valid components ; as valid components
freebusyc = "BEGIN" ":" "VFREEBUSY" CRLF freebusyc = "BEGIN" ":" "VFREEBUSY" CRLF
fbprop *participantc *locationc *resourcec fbprop *participantc *locationc *resourcec
"END" ":" "VFREEBUSY" CRLF "END" ":" "VFREEBUSY" CRLF
; Addition of property STYLED-DESCRIPTION ; Addition of property STYLED-DESCRIPTION
fbprop =/ *styleddescription fbprop =/ *styleddescription
5. New Property Parameters 5. New Property Parameters
5.1. Order 5.1. Order
Parameter name: ORDER Parameter name: ORDER
Purpose: To define ordering for the associated property. Purpose: This parameter defines ordering for the associated
property.
Format Definition:
This parameter is defined by the following notation: Format Definition: This parameter is defined by the following
notation:
orderparam = "ORDER" "=" integer orderparam = "ORDER" "=" integer
; Must be greater than or equal to 1 ; Must be greater than or equal to 1
Description: The ORDER parameter is OPTIONAL and is used to indicate Description: The "ORDER" parameter is OPTIONAL and is used to
the relative ordering of the corresponding instance of a property. indicate the relative ordering of the corresponding instance of a
Its value MUST be an integer greater than or equal to 1 that property. Its value MUST be an integer greater than or equal to 1
specifies the order with 1 being the first in the ordering. that specifies the order, with 1 being the first in the ordering.
When the parameter is absent, the default MUST be to interpret the When the parameter is absent, the default MUST be to interpret the
property instance as being ordered last, that is, the property property instance as being ordered last, that is, the property
will appear after any other instances of the same property with will appear after any other instances of the same property with
any value of ORDER. any value of ORDER.
When any ORDER parameters have the same value all the associated When any "ORDER" parameters have the same value, all the
properties appear as a group within which there is no defined associated properties appear as a group within which there is no
order. defined order.
Note that the value of this parameter is to be interpreted only in Note that the value of this parameter is to be interpreted only in
relation to values assigned to other corresponding instances of relation to values assigned to other corresponding instances of
the same property in the same entity. the same property in the same entity.
This parameter MUST NOT be applied to a property that does not This parameter MUST NOT be applied to a property that does not
allow multiple instances. allow multiple instances.
Example uses: The ORDER may be applied to the PARTICIPANT-TYPE Example uses: The ORDER may be applied to the "PARTICIPANT-TYPE"
property to indicate the relative importance of the participant, property to indicate the relative importance of the participant,
for example as a sponsor or a performer. For example, ORDER=1 for example, as a sponsor or a performer. For example, ORDER=1
could define the principal performer or soloist. could define the principal performer or soloist.
5.2. Schema 5.2. Schema
Parameter Name: SCHEMA Parameter Name: SCHEMA
Purpose: To specify the schema used for the content of a Purpose: This parameter specifies the schema used for the content of
"STRUCTURED-DATA" property value. a "STRUCTURED-DATA" property value.
Format Definition:
This parameter is defined by the following notation: Format Definition: This parameter is defined by the following
notation:
schemaparam = "SCHEMA" "=" DQUOTE uri DQUOTE schemaparam = "SCHEMA" "=" DQUOTE uri DQUOTE
Description: This property parameter SHOULD be specified on Description: This property parameter SHOULD be specified on
"STRUCTURED-DATA" properties. When present it provides "STRUCTURED-DATA" properties. When present, it provides
identifying information about the nature of the content of the identifying information about the nature of the content of the
corresponding "STRUCTURED-DATA" property value. This can be used corresponding "STRUCTURED-DATA" property value. This can be used
to supplement the media type information provided by the "FMTTYPE" to supplement the media type information provided by the "FMTTYPE"
parameter on the corresponding property. parameter on the corresponding property.
Example: Example:
STRUCTURED-DATA;FMTTYPE=application/ld+json;
STRUCTURED-DATA;FMTTYPE=application/ld+json; SCHEMA="https://schema.org/FlightReservation";
SCHEMA="https://schema.org/FlightReservation"; ENCODING=BASE64;VALUE=BINARY:ICAgIDxzY3JpcHQgdHlwZT0iYXBwb
ENCODING=BASE64;VALUE=BINARY:ICAgIDxzY3JpcHQgdHlwZT0iYXBwb GljYXRpb24vbGQranNvbiI+CiAgICB7CiAgICAgICJAY29
GljYXRpb24vbGQranNvbiI+CiAgICB7CiAgICAgICJAY29 udGV4dCI6ICJodHRwOi8vc2NoZW1hLm9yZyIsCiAgICAgICJAdHlwZSI
udGV4dCI6ICJodHRwOi8vc2NoZW1hLm9yZyIsCiAgICAgICJAdHlwZSI 6ICJGbGlnaHRSZXNlcnZhdGlvbiIsCiAgICAgICJyZXNlcnZhdGlvbkl
6ICJGbGlnaHRSZXNlcnZhdGlvbiIsCiAgICAgICJyZXNlcnZhdGlvbkl kIjogIlJYSjM0UCIsCiAgICAgICJyZXNlcnZhdGlvblN0YXR1cyI6ICJ
kIjogIlJYSjM0UCIsCiAgICAgICJyZXNlcnZhdGlvblN0YXR1cyI6ICJ odHRwOi8vc2NoZW1hLm9yZy9SZXNlcnZhdGlvbkNvbmZpcm1lZCIsCiA
odHRwOi8vc2NoZW1hLm9yZy9SZXNlcnZhdGlvbkNvbmZpcm1lZCIsCiA gICAgICJwYXNzZW5nZXJQcmlvcml0eVN0YXR1cyI6ICJGYXN0IFRyYWN
gICAgICJwYXNzZW5nZXJQcmlvcml0eVN0YXR1cyI6ICJGYXN0IFRyYWN rIiwKICAgICAgInBhc3NlbmdlclNlcXVlbmNlTnVtYmVyIjogIkFCQzE
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5.3. Derived 5.3. Derived
Parameter Name: DERIVED Parameter Name: DERIVED
Purpose: To specify that the value of the associated property is Purpose: This parameter specifies that the value of the associated
derived from some other property value or values. property is derived from some other property value or values.
Format Definition:
This parameter is defined by the following notation: Format Definition: This parameter is defined by the following
notation:
derivedparam = "DERIVED" "=" ("TRUE" / "FALSE") derivedparam = "DERIVED" "=" ("TRUE" / "FALSE")
; Default is FALSE ; Default is FALSE
Description: This property parameter MAY be specified on any Description: This property parameter MAY be specified on any
property when the value is derived from some other property or property when the value is derived from some other property or
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
DESCRIPTION property with FMTTYPE="text/html" and DERIVED=TRUE and "STYLED-DESCRIPTION" property with FMTTYPE="text/html" and
a value created from the rtf value. DERIVED=TRUE, as well as a value created from the rtf value.
Example: Example:
STYLED-DESCRIPTION;FMTTYPE=text/html;
STYLED-DESCRIPTION;FMTTYPE=text/html; DERIVED=TRUE:<html>...</html>
DERIVED=TRUE:<html>...</html>
6. New Properties 6. New Properties
This specification makes use of the NAME property which is defined in This specification makes use of the "NAME" property, which is defined
[RFC7986] in [RFC7986].
6.1. Location Type 6.1. Location Type
Property name: LOCATION-TYPE Property Name: LOCATION-TYPE
Purpose: To specify the type(s) of a location. Purpose: This property specifies the type(s) of a location.
Value type: The value type for this property is TEXT. The allowable Value Type: The value type for this property is TEXT. The allowable
values are defined below. values are defined below.
Description: This property MAY be specified in VLOCATION components Description: This property MAY be specified in "VLOCATION"
and provides a way to differentiate multiple locations. For components and provides a way to differentiate multiple locations.
example, it allows event producers to provide location information For example, it allows event producers to provide location
for the venue and the parking. information for the venue and the parking.
Format Definition:
This property is defined by the following notation: Format Definition: This property is defined by the following
notation:
loctype = "LOCATION-TYPE" loctypeparam ":" loctype = "LOCATION-TYPE" loctypeparam ":"
text *("," text) text *("," text)
CRLF CRLF
loctypeparam = *(";" other-param) loctypeparam = *(";" other-param)
Multiple values may be used if the location has multiple purposes, Multiple values may be used if the location has multiple purposes,
for example a hotel and a restaurant. for example, a hotel and a restaurant.
Values for this parameter are taken from the values defined in Values for this parameter are taken from the values defined in
[RFC4589] section 3. New location types SHOULD be registered in Section 3 of [RFC4589]. New location types SHOULD be registered
the manner laid down in section 5 of that specification. in the manner laid down in Section 5 of [RFC4589].
6.2. Participant Type 6.2. Participant Type
Property name: PARTICIPANT-TYPE Property Name: PARTICIPANT-TYPE
Purpose: To specify the type of participant. Purpose: This property specifies the type of participant.
Value type: The value type for this property is TEXT. The allowable Value Type: The value type for this property is TEXT. The allowable
values are defined below. values are defined below.
Property Parameters: Non-standard parameters can be specified on Property Parameters: Nonstandard parameters can be specified on this
this property. property.
Conformance: This property MUST be specified once within a Conformance: This property MUST be specified once within a
PARTICIPANT component. "PARTICIPANT" component.
Description: This property defines the type of participation in Description: This property defines the type of participation in
events or tasks. Participants can be individuals or events or tasks. Participants can be individuals or
organizations, for example a soccer team, the spectators, or the organizations, for example, a soccer team, the spectators, or the
musicians. musicians.
Format Definition: Format Definition: This property is defined by the following
notation:
This property is defined by the following notation:
participanttype = "PARTICIPANT-TYPE" partvalueparam ":"
partvalue CRLF
partvalue = ("ACTIVE" participanttype = "PARTICIPANT-TYPE" partvalueparam ":"
/ "INACTIVE" partvalue CRLF
/ "SPONSOR"
/ "CONTACT"
/ "BOOKING-CONTACT"
/ "EMERGENCY-CONTACT"
/ "PUBLICITY-CONTACT"
/ "PLANNER-CONTACT"
/ "PERFORMER"
/ "SPEAKER"
/ iana-token) ; Other IANA-registered
; values
partvalueparam = *(";" other-param) partvalue = ("ACTIVE"
/ "INACTIVE"
/ "SPONSOR"
/ "CONTACT"
/ "BOOKING-CONTACT"
/ "EMERGENCY-CONTACT"
/ "PUBLICITY-CONTACT"
/ "PLANNER-CONTACT"
/ "PERFORMER"
/ "SPEAKER"
/ iana-token) ; Other IANA-registered
; values
Example: partvalueparam = *(";" other-param)
The following is an example of this property: Example: The following is an example of this property.
PARTICIPANT-TYPE:SPEAKER PARTICIPANT-TYPE:SPEAKER
The registered values for the PARTICIPANT-TYPE property have the The registered values for the "PARTICIPANT-TYPE" property have the
meanings described here: meanings described here:
ACTIVE: A participant taking an active role - for example a team ACTIVE: A participant taking an active role -- for example, a team
member. member.
INACTIVE: A participant taking an inactive role - for example an INACTIVE: A participant taking an inactive role -- for example, an
audience member. audience member.
SPONSOR: A sponsor of the event. The ORDER parameter may be used SPONSOR: A sponsor of the event. The "ORDER" parameter may be used
with this participant type to define the relative order of with this participant type to define the relative order of
multiple sponsors. multiple sponsors.
CONTACT: Contact information for the event. The ORDER parameter may CONTACT: Contact information for the event. The "ORDER" parameter
be used with this participant type to define the relative order of may be used with this participant type to define the relative
multiple contacts. order of multiple contacts.
BOOKING-CONTACT: Contact information for reservations or payment BOOKING-CONTACT: Contact information for reservations or payment.
EMERGENCY-CONTACT: Contact in case of emergency EMERGENCY-CONTACT: Contact in case of emergency.
PUBLICITY-CONTACT: Contact for publicity PUBLICITY-CONTACT: Contact for publicity.
PLANNER-CONTACT: Contact for the event planner or organizer
PERFORMER: A performer - for example the soloist or the accompanist. PLANNER-CONTACT: Contact for the event planner or organizer.
The ORDER parameter may be used with this participant type to
define the relative order of multiple performers. For example,
ORDER=1 could define the principal performer or soloist.
SPEAKER: Speaker at an event PERFORMER: A performer -- for example, the soloist or the
accompanist. The "ORDER" parameter may be used with this
participant type to define the relative order of multiple
performers. For example, ORDER=1 could define the principal
performer or soloist.
SPEAKER: Speaker at an event.
6.3. Resource Type 6.3. Resource Type
Property name: RESOURCE-TYPE Property Name: RESOURCE-TYPE
Purpose: To specify the type of resource. Purpose: This property specifies the type of resource.
Value type: The value type for this property is TEXT. The allowable Value Type: The value type for this property is TEXT. The allowable
values are defined below. values are defined below.
Format Definition: Format Definition: This property is defined by the following
notation:
This property is defined by the following notation:
restypeprop = "RESOURCE-TYPE" restypeparam ":" restypeprop = "RESOURCE-TYPE" restypeparam ":"
restypevalue CRLF restypevalue CRLF
restypevalue = ("ROOM" restypevalue = ("ROOM"
/ "PROJECTOR" / "PROJECTOR"
/ "REMOTE-CONFERENCE-AUDIO" / "REMOTE-CONFERENCE-AUDIO"
/ "REMOTE-CONFERENCE-VIDEO" / "REMOTE-CONFERENCE-VIDEO"
/ iana-token) ; Other IANA-registered / iana-token) ; Other IANA-registered
; values ; values
restypeparam = *(";" other-param) restypeparam = *(";" other-param)
Description: This property MAY be specified in VRESOURCE components Description: This property MAY be specified in "VRESOURCE"
and provides a way to differentiate multiple resources. components and provides a way to differentiate multiple resources.
The registered values are described below. New resource types The registered values are described below. New resource types
SHOULD be registered in the manner laid down in this SHOULD be registered in the manner laid down in this
specification. specification.
ROOM: A room for the event/meeting. ROOM: A room for the event/meeting.
PROJECTOR: Projection equipment. PROJECTOR: Projection equipment.
REMOTE-CONFERENCE-AUDIO: Audio remote conferencing facilities. REMOTE-CONFERENCE-AUDIO: Audio remote conferencing facilities.
REMOTE-CONFERENCE-VIDEO: Video remote conferencing facilities. REMOTE-CONFERENCE-VIDEO: Video remote conferencing facilities.
6.4. Calendar Address 6.4. Calendar Address
Property name: CALENDAR-ADDRESS Property Name: CALENDAR-ADDRESS
Purpose: To specify the calendar address for a participant. Purpose: This property specifies the calendar address for a
participant.
Value type: CAL-ADDRESS Value Type: CAL-ADDRESS
Property Parameters: IANA-registered, or non-standard property Property Parameters: IANA-registered or nonstandard property
parameters can be specified on this property. parameters can be specified on this property.
Conformance: This property MAY be specified once within a Conformance: This property MAY be specified once within a
PARTICIPANT component. "PARTICIPANT" component.
Description: This property provides a calendar user address for the Description: This property provides a calendar user address for the
participant. If there is an ATTENDEE property with the same value participant. If there is an "ATTENDEE" property with the same
then the participant is schedulable. value, then the participant is schedulable.
Format Definition:
This property is defined by the following notation: Format Definition: This property is defined by the following
notation:
calendaraddress = "CALENDAR-ADDRESS" caladdressparam ":" calendaraddress = "CALENDAR-ADDRESS" caladdressparam ":"
cal-address CRLF cal-address CRLF
caladdressparam = *(";" other-param) caladdressparam = *(";" other-param)
6.5. Styled-Description 6.5. Styled-Description
Property name: STYLED-DESCRIPTION Property Name: STYLED-DESCRIPTION
Purpose: This property provides for one or more rich-text Purpose: This property provides for one or more rich-text
descriptions to replace that provided by the DESCRIPTION property. descriptions to replace that provided by the "DESCRIPTION"
property.
Value type: There is no default value type for this property. The Value Type: There is no default value type for this property. The
value type can be set to URI or TEXT. Other text-based value value type can be set to URI or TEXT. Other text-based value
types can be used when defined in the future. Clients MUST ignore types can be used when defined in the future. Clients MUST ignore
any properties with value types they do not understand. any properties with value types they do not understand.
Property Parameters: IANA-registered, non-standard, id, alternate Property Parameters: IANA-registered, nonstandard, id, alternate
text representation, format type, derived and language property text representation, format type, derived, and language property
parameters can be specified on this property. parameters can be specified on this property.
Conformance: The property can be specified multiple times in the Conformance: The property can be specified multiple times in the
"VEVENT", "VTODO", "VJOURNAL", "VFREEBUSY", "PARTICIPANT", or "VEVENT", "VTODO", "VJOURNAL", "VFREEBUSY", "PARTICIPANT", or
"VALARM" calendar components. "VALARM" calendar components.
If it does appear more than once there MUST be exactly one If it does appear more than once, there MUST be exactly one
instance of the property with no DERIVED parameter or instance of the property with no "DERIVED" parameter or
DERIVED=FALSE. All others MUST have DERIVED=TRUE. DERIVED=FALSE. All others MUST have DERIVED=TRUE.
Additionally, if there is one or more STYLED-DESCRIPTION property Additionally, if there is one or more "STYLED-DESCRIPTION"
then the DESCRIPTION property should be either absent or have the property, then the "DESCRIPTION" property should either be absent
parameter DERIVED=TRUE. or have the parameter DERIVED=TRUE.
Description: This property supports rich-text descriptions, for Description: This property supports rich-text descriptions, for
example HTML. Event publishers typically wish to provide more and example, HTML. Event publishers typically wish to provide more
better formatted information about the event. and better-formatted information about the event.
This property is used in the "VEVENT" and "VTODO" to capture This property is used in the "VEVENT" and "VTODO" components to
lengthy textual descriptions associated with the activity. This capture lengthy textual descriptions associated with the activity.
property is used in the "VJOURNAL" calendar component to capture This property is used in the "VJOURNAL" calendar component to
one or more textual journal entries. This property is used in the capture one or more textual journal entries. This property is
"VALARM" calendar component to capture the display text for a used in the "VALARM" calendar component to capture the display
DISPLAY category of alarm, and to capture the body text for an text for a DISPLAY category of alarm and to capture the body text
EMAIL category of alarm. In the PARTICIPANT component it provides for an EMAIL category of alarm. In the "PARTICIPANT" component,
a detailed description of the participant. it provides a detailed description of the participant.
VALUE=TEXT is used to provide rich-text inline as the property VALUE=TEXT is used to provide rich text inline as the property
value. value.
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" and process the content as defined in type "text/html" and process the content as defined in
[W3C.REC-html51-20171003] [W3C.REC-html51-20171003].
Multiple STYLED-DESCRIPTION properties may be used to provide
different formats or different language variants. However all but
one MUST have DERIVED=TRUE.
Format Definition:
This property is defined by the following notation:
styleddescription = "STYLED-DESCRIPTION" styleddescparam ":"
styleddescval CRLF
styleddescparam = ; the elements herein may appear in any order,
; and the order is not significant.
(";" "VALUE" "=" ("URI" / "TEXT")) Multiple "STYLED-DESCRIPTION" properties may be used to provide
different formats or different language variants. However, all
but one MUST have DERIVED=TRUE.
[";" altrepparam] Format Definition: This property is defined by the following
[";" languageparam] notation:
[";" fmttypeparam]
[";" derivedparam]
*(";" other-param) styleddescription = "STYLED-DESCRIPTION" styleddescparam ":"
styleddescval CRLF
styleddescval = ( uri / text ) styleddescparam = *(
;Value MUST match value type ; The following is REQUIRED
; but MUST NOT occur more than once.
;
(";" "VALUE" "=" ("URI" / "TEXT")) /
;
; The following are OPTIONAL
; but MUST NOT occur more than once.
;
(";" altrepparam) / (";" languageparam) /
(";" fmttypeparam) / (";" derivedparam) /
;
; The following is OPTIONAL
; and MAY occur more than once.
;
(";" other-param)
)
Example: styleddescval = ( uri / text )
;Value MUST match value type
The following is an example of this property. It points to an html Example: The following is an example of this property. It points to
description. an HTML description.
STYLED-DESCRIPTION;VALUE=URI:http://example.org/desc001.html STYLED-DESCRIPTION;VALUE=URI:http://example.org/desc001.html
6.6. Structured-Data 6.6. Structured-Data
Property Name: STRUCTURED-DATA Property Name: STRUCTURED-DATA
Purpose: This property specifies ancillary data associated with the Purpose: This property specifies ancillary data associated with the
calendar component. calendar component.
Value Type: There is no default value type for this property. The Value Type: There is no default value type for this property. The
value type can be set to TEXT, BINARY or URI value type can be set to TEXT, BINARY, or URI.
Property Parameters: IANA-registered, non-standard, inline encoding Property Parameters: IANA-registered, nonstandard, 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 and schema parameters can be specified property. The format type and schema parameters can be specified
on this property and MUST be present for text or inline binary on this property and MUST be present for text or inline binary
encoded content information. encoded content information.
Conformance: This property can be specified multiple times in an Conformance: This property can be specified multiple times in an
iCalendar object. Typically it would be used in "VEVENT", "VTODO" iCalendar object. Typically, it would be used in the "VEVENT",
or "VJOURNAL" calendar components. "VTODO", or "VJOURNAL" calendar components.
Description: The existing properties in iCalendar cover key elements Description: The existing properties in iCalendar cover key elements
of events and tasks such as start time, end time, location, of events and tasks, such as start time, end time, location,
summary, etc. However, different types of events often have other summary, etc. However, different types of events often have other
specific "fields" that it is useful to include in the calendar specific "fields" that are useful to include in the calendar data.
data. For example, an event representing an airline flight could For example, an event representing an airline flight could include
include the airline, flight number, departure and arrival airport the airline, flight number, departure and arrival airport codes,
codes, check-in and gate-closing times etc. As another example, a check-in and gate-closing times, etc. As another example, a
sporting event might contain information about the type of sport, sporting event might contain information about the type of sport,
the home and away teams, the league the teams are in, information the home and away teams, the league the teams are in, information
about nearby parking, etc. about nearby parking, etc.
This property is used to specify ancillary data in some structured This property is used to specify ancillary data in some structured
format either directly (inline) as a "TEXT" or "BINARY" value or format, either directly (inline) as a "TEXT" or "BINARY" value or
as a link via a "URI" value. as a link via a "URI" value.
Rather than define new iCalendar properties for the variety of Rather than define new iCalendar properties for the variety of
event types that might occur, it would be better to leverage event types that might occur, it would be better to leverage
existing schemas for such data. For example, schemas available at existing schemas for such data. For example, schemas available at
https://schema.org include different event types. By using <https://schema.org> include different event types. By using
standard schemas, interoperability can be improved between standard schemas, interoperability can be improved between
calendar clients and non-calendaring systems that wish to generate calendar clients and noncalendaring systems that wish to generate
or process the data. or process the data.
This property allows the direct inclusion of ancillary data whose This property allows the direct inclusion of ancillary data whose
schema is defined elsewhere. This property also includes schema is defined elsewhere. This property also includes
parameters to clearly identify the type of the schema being used parameters to clearly identify the type of the schema being used
so that clients can quickly and easily spot what is relevant so that clients can quickly and easily spot what is relevant
within the calendar data and present that to users or process it within the calendar data and present that to users or process it
within the calendaring system. within the calendaring system.
iCalendar does support an "ATTACH" property which can be used to iCalendar does support an "ATTACH" property, which can be used to
include documents or links to documents within the calendar data. include documents or links to documents within the calendar data.
However, that property does not allow data to be included as a However, that property does not allow data to be included as a
"TEXT" value (a feature that "STRUCTURED-DATA" does allow), plus "TEXT" value (a feature that "STRUCTURED-DATA" does allow), plus
attachments are often treated as "opaque" data to be processed by attachments are often treated as "opaque" data to be processed by
some other system rather than the calendar client. Thus the some other system rather than the calendar client. Thus, the
existing "ATTACH" property is not sufficient to cover the specific existing "ATTACH" property is not sufficient to cover the specific
needs of inclusion of schema data. Extending the "ATTACH" needs of inclusion of schema data. Extending the "ATTACH"
property to support a new value type would likely cause property to support a new value type would likely cause
interoperability problems. Additionally some implementations interoperability problems. Additionally, some implementations
manage attachments by stripping them out and replacing with a link manage attachments by stripping them out and replacing with a link
to the resource. Thus a new property to support inclusion of to the resource. Thus, a new property to support inclusion of
schema data is warranted. schema data is warranted.
Format Definition: Format Definition: This property is defined by the following
notation:
This property is defined by the following notation:
sdataprop = "STRUCTURED-DATA" sdataparam ":"
sdataval CRLF
sdataparam = ; all parameter elements may appear in any order,
; and the order is not significant.
(sdataparamtext / sdataparambin / sdataparamuri)
*(";" other-param)
sdataparamtext = ";VALUE=TEXT"
";" fmttypeparam
";" schemaparam
sdataparambin = ";VALUE=BINARY"
";ENCODING=BASE64"
";" fmttypeparam
";" schemaparam
sdataparamuri = ";VALUE=URI" sdataprop = "STRUCTURED-DATA" sdataparam
[";" fmttypeparam] (
[";" schemaparam] ";" "VALUE" "=" "TEXT"
":" text
) /
(
";" "ENCODING" "=" "BASE64"
";" "VALUE" "=" "BINARY"
";" binary
) /
(
";" "VALUE" "=" "URI"
":" uri
)
CRLF
sdataval = ( binary / text /uri ) sdataparam = *(
; value MUST match value type ;
; The following is OPTIONAL for a URI value,
; REQUIRED for a TEXT or BINARY value,
; and MUST NOT occur more than once.
;
(";" fmttypeparam) /
(";" schemaparam) /
;
; The following is OPTIONAL
; and MAY occur more than once.
;
(";" other-param)
;
)
Example: The following is an example of this property: Example: The following is an example of this property.
STRUCTURED-DATA;FMTTYPE=application/ld+json; STRUCTURED-DATA;FMTTYPE=application/ld+json;
SCHEMA="https://schema.org/SportsEvent"; SCHEMA="https://schema.org/SportsEvent";
VALUE=TEXT:{\n VALUE=TEXT:{\n
"@context": "http://schema.org"\,\n "@context": "http://schema.org"\,\n
"@type": "SportsEvent"\,\n "@type": "SportsEvent"\,\n
"homeTeam": "Pittsburgh Pirates"\,\n "homeTeam": "Pittsburgh Pirates"\,\n
"awayTeam": "San Francisco Giants"\n "awayTeam": "San Francisco Giants"\n
}\n }\n
7. New Components 7. New Components
7.1. Participant 7.1. 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 task. an event or task.
Conformance: This component can be specified multiple times in a Conformance: This component can be specified multiple times in a
"VEVENT", "VTODO", "VJOURNAL" or "VFREEBUSY" calendar component. "VEVENT", "VTODO", "VJOURNAL", or "VFREEBUSY" calendar component.
Description: This component provides information about a participant Description: This component provides information about a participant
in a calendar component. A participant may be an attendee in a in a calendar component. A participant may be an attendee in a
scheduling sense and the ATTENDEE property may be specified in scheduling sense, and the "ATTENDEE" property may be specified in
addition. Participants can be individuals or organizations, for addition. Participants can be individuals or organizations, for
example a soccer team, the spectators or the musicians. example, a soccer team, the spectators, or the musicians.
STRUCTURED-DATA properties if present may refer to definitions of
the participant - such as a vCard.
The CALENDAR-ADDRESS property if present will provide a cal- "STRUCTURED-DATA" properties, if present, may refer to definitions
address. If an ATTENDEE property has the same value the of the participant -- such as a vCard.
participant is considered schedulable. The PARTICIPANT component
can be used to contain additional meta-data related to the
attendee.
Format Definition: The "CALENDAR-ADDRESS" property, if present, will provide a cal-
address. If an "ATTENDEE" property has the same value, the
participant is considered schedulable. The "PARTICIPANT"
component can be used to contain additional metadata related to
the attendee.
This component is defined by the following notation: Format Definition: This component is defined by the following
notation:
participantc = "BEGIN" ":" "PARTICIPANT" CRLF participantc = "BEGIN" ":" "PARTICIPANT" CRLF
partprop *locationc *resourcec partprop *locationc *resourcec
"END" ":" "PARTICIPANT" CRLF "END" ":" "PARTICIPANT" CRLF
partprop = ; the elements herein may appear in any order, partprop = *(
; and the order is not significant. ;
; The following are REQUIRED
uid ; but MUST NOT occur more than once.
participanttype ;
participanttype / uid /
[calendaraddress] ;
[created] ; The following are OPTIONAL
[description] ; but MUST NOT occur more than once.
[dtstamp] ;
[geo] calendaraddress / created / description / dtstamp /
[last-mod] geo / last-mod / priority / seq /
[priority] status / summary / url /
[seq] ;
[status] ; The following are OPTIONAL
[summary] ; and MAY occur more than once.
[url] ;
attach / categories / comment
*attach contact / location / rstatus / related /
*categories resources / strucloc / strucres /
*comment styleddescription / sdataprop / iana-prop
*contact ;
*location )
*rstatus
*related
*resources
*strucloc
*strucres
*styleddescription
*sdataprop
*iana-prop
Note: When the PRIORITY is supplied it defines the ordering of Note: When the "PRIORITY" property is supplied, it defines the
PARTICIPANT components with the same value for the PARTICIPANT- ordering of "PARTICIPANT" components with the same value for the
TYPE property. "PARTICIPANT-TYPE" property.
Privacy Issues: When a LOCATION is supplied it provides information Privacy Issues: When a "LOCATION" property is supplied, it provides
about the location of a participant at a given time or times. information about the location of a participant at a given time or
This may represent an unacceptable privacy risk for some times. This may represent an unacceptable privacy risk for some
participants. User agents MUST NOT broadcast this information participants. User agents MUST NOT broadcast this information
without the participant's express permission. For further without the express permission of the participants whose location
comments see Section 10 would be exposed. For further comments, see Section 10.
Example:
The following is an example of this component. It contains a Example: The following is an example of this component. It contains
STRUCTURED-DATA property which points to a vCard providing a "STRUCTURED-DATA" property that points to a vCard providing
information about the event participant. information about the event participant.
BEGIN:PARTICIPANT BEGIN:PARTICIPANT
UID: em9lQGZvb2GFtcGxlLmNvbQ UID: em9lQGZvb2GFtcGxlLmNvbQ
PARTICIPANT-TYPE:PERFORMER PARTICIPANT-TYPE:PERFORMER
STRUCTURED-DATA;VALUE=URI: STRUCTURED-DATA;VALUE=URI:
http://dir.example.com/vcard/aviolinist.vcf 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
UID: em9lQGZvb2GFtcGxlLmNvbQ
STRUCTURED-DATA;VALUE=URI;
http://dir.example.com/vcard/contacts/contact1.vcf
PARTICIPANT-TYPE:CONTACT
DESCRIPTION:A contact
END:PARTICIPANT
Example: BEGIN:PARTICIPANT
UID: em9lQGZvb2GFtcGxlLmNvbQ
STRUCTURED-DATA;VALUE=URI;
http://dir.example.com/vcard/contacts/contact1.vcf
PARTICIPANT-TYPE:CONTACT
DESCRIPTION:A contact
END:PARTICIPANT
The following is an example for a participant with contact and Example: The following is an example for a participant with contact
location. and location.
BEGIN:PARTICIPANT BEGIN:PARTICIPANT
UID: em9lQGZvb2GFtcGxlLmNdrt UID: em9lQGZvb2GFtcGxlLmNdrt
STRUCTURED-DATA;VALUE=URI; STRUCTURED-DATA;VALUE=URI;
http://dir.example.com/vcard/contacts/my-card.vcf http://dir.example.com/vcard/contacts/my-card.vcf
PARTICIPANT-TYPE:SPEAKER PARTICIPANT-TYPE:SPEAKER
DESCRIPTION:A participant DESCRIPTION:A participant
BEGIN:VLOCATION BEGIN:VLOCATION
UID:123456-abcdef-98765432 UID:123456-abcdef-98765432
NAME:My home location NAME:My home location
STRUCTURED-DATA;VALUE=URI: STRUCTURED-DATA;VALUE=URI:
http://dir.example.com/addresses/my-home.vcf http://dir.example.com/addresses/my-home.vcf
END:VLOCATION END:VLOCATION
END:PARTICIPANT END:PARTICIPANT
7.1.1. Schedulable Participant 7.1.1. Schedulable Participant
A PARTICIPANT component may represent someone or something that needs A "PARTICIPANT" component may represent someone or something that
to be scheduled as defined for ATTENDEE in [RFC5545] and [RFC5546]. needs to be scheduled, as defined for ATTENDEE in [RFC5545] and
The PARTICIPANT component may also represent someone or something [RFC5546]. The "PARTICIPANT" component may also represent someone or
that is NOT to receive scheduling messages. something that is NOT to receive scheduling messages.
For backwards compatibility wuth existing clients and servers when For backwards compatibility with existing clients and servers when
used to schedule events and tasks the ATTENDEE property MUST be used used to schedule events and tasks, the "ATTENDEE" property MUST be
to specify the sheduling parameters as defined for that property. used to specify the scheduling parameters as defined for that
property.
For other, future uses the CALENDAR-ADDRESS property MUST be used to For other, future uses, the "CALENDAR-ADDRESS" property MUST be used
specify those parameters. to specify those parameters.
A PARTICIPANT component is defined to be schedulable if A "PARTICIPANT" component is defined to be schedulable if:
o It contains a CALENDAR-ADDRESS property * it contains a "CALENDAR-ADDRESS" property and
o That property value is the same as the value for an ATTENDEE * that property value is the same as the value for an "ATTENDEE"
property. property.
If both of these conditions apply then the participant defined by the If both of these conditions apply, then the participant defined by
value of the URL property will take part in scheduling operations as the value of the URL property will take part in scheduling
defined in [RFC5546]. operations, as defined in [RFC5546].
An appropriate use for the PARTICIPANT component in scheduling would An appropriate use for the "PARTICIPANT" component in scheduling
be to store SEQUENCE and DTSTAMP properties associated with replies would be to store "SEQUENCE" and "DTSTAMP" properties associated with
from each ATTENDEE. A LOCATION property within the PARTICIPANT replies from each "ATTENDEE" property. A "LOCATION" property within
component might allow better selection of meeting times when the "PARTICIPANT" component might allow better selection of meeting
participants are in different timezones. times when participants are in different time zones.
7.2. Location 7.2. Location
Component name: VLOCATION Component name: VLOCATION
Purpose: This component provides rich information about the location Purpose: This component provides rich information about the location
of an event using the structured data property or optionally a of an event using the structured data property or, optionally, a
plain text typed value. plain-text typed value.
Conformance: This component can be specified multiple times in a Conformance: This component can be specified multiple times in a
"VEVENT", "VTODO", "VJOURNAL", "VFREEBUSY" or "PARTICIPANT" "VEVENT", "VTODO", "VJOURNAL", "VFREEBUSY", or "PARTICIPANT"
calendar component. calendar component.
Description: There may be a number of locations associated with an Description: There may be a number of locations associated with an
event. This component provides detailed information about a event. This component provides detailed information about a
location. location.
When used in a component the value of this property provides When used in a component, the value of this property provides
information about the event venue or of related services such as information about the event venue or of related services, such as
parking, dining, stations etc.. parking, dining, stations, etc.
STRUCTURED-DATA properties if present may refer to representations
of the location - such as a vCard.
Format Definition: "STRUCTURED-DATA" properties, if present, may refer to
representations of the location -- such as a vCard.
This component is defined by the following notation: Format Definition: This component is defined by the following
notation:
locationc = "BEGIN" ":" "VLOCATION" CRLF locationc = "BEGIN" ":" "VLOCATION" CRLF
locprop locprop
"END" ":" "VLOCATION" CRLF "END" ":" "VLOCATION" CRLF
locprop = ; the elements herein may appear in any order, locprop = *(
; and the order is not significant. ;
; The following are REQUIRED
uid ; but MUST NOT occur more than once.
;
[name] uid /
[description] ;
[geo] ; The following are OPTIONAL
[loctype] ; but MUST NOT occur more than once.
;
*sdataprop description / geo / loctype / name
*iana-prop ;
; The following are OPTIONAL
The NAME property is defined in [RFC7986] ; and MAY occur more than once.
;
sdataprop / iana-prop
)
Example: The "NAME" property is defined in [RFC7986].
The following is an example of this component. It points to a venue. Example: The following is an example of this component. It points
to a venue.
BEGIN:VLOCATION BEGIN:VLOCATION
UID:123456-abcdef-98765432 UID:123456-abcdef-98765432
NAME:The venue NAME:The venue
STRUCTURED-DATA;VALUE=URI: STRUCTURED-DATA;VALUE=URI:
http://dir.example.com/venues/big-hall.vcf http://dir.example.com/venues/big-hall.vcf
END:VLOCATION END:VLOCATION
7.3. Resource 7.3. Resource
Component name: VRESOURCE Component name: VRESOURCE
Purpose: This component provides a typed reference to external Purpose: This component provides a typed reference to external
information about a resource or optionally a plain text typed information about a resource or, optionally, a plain-text typed
value. Typically a resource is anything that might be required or value. Typically, a resource is anything that might be required
used by a calendar entity and possibly has a directory entry. or used by a calendar entity and possibly has a directory entry.
Conformance: This component can be specified multiple times in a Conformance: This component can be specified multiple times in a
"VEVENT", "VTODO", "VJOURNAL", "VFREEBUSY" or "PARTICIPANT" "VEVENT", "VTODO", "VJOURNAL", "VFREEBUSY", or "PARTICIPANT"
calendar component. calendar component.
Description: When used in a component this component provides Description: When used in a component, this component provides
information about resources used for the event such as rooms, information about resources used for the event, such as rooms,
projectors, conferencing capabilities. projectors, and conferencing capabilities.
The RESOURCE-TYPE value registry provides a place in which The RESOURCE-TYPE value registry provides a place in which
resource types may be registered. resource types may be registered.
STRUCTURED-DATA properties if present may refer to representations "STRUCTURED-DATA" properties, if present, may refer to
of the resource - such as a vCard. representations of the resource -- such as a vCard.
Format Definition:
This component is defined by the following notation: Format Definition: This component is defined by the following
notation:
resourcec = "BEGIN" ":" "VRESOURCE" CRLF resourcec = "BEGIN" ":" "VRESOURCE" CRLF
resprop resprop
"END" ":" "VRESOURCE" CRLF "END" ":" "VRESOURCE" CRLF
resprop = ; the elements herein may appear in any order, resprop = *(
; and the order is not significant. ;
; The following are REQUIRED
uid ; but MUST NOT occur more than once.
;
[name] uid /
[description] ;
[geo] ; The following are OPTIONAL
[restype] ; but MUST NOT occur more than once.
;
*sdataprop description / geo / name / restype /
*iana-prop ;
; The following are OPTIONAL
The NAME property is defined in [RFC7986] ; and MAY occur more than once.
;
sdataprop / iana-prop
)
Example: The "NAME" property is defined in [RFC7986].
The following is an example of this component. It refers to a Example: The following is an example of this component. It refers
projector. to a projector.
BEGIN:VRESOURCE BEGIN:VRESOURCE
UID:456789-abcdef-98765432 UID:456789-abcdef-98765432
NAME:The projector NAME:The projector
RESOURCE-TYPE:projector RESOURCE-TYPE:projector
STRUCTURED-DATA;VALUE=URI:http://dir.example.com/projectors/3d.vcf STRUCTURED-DATA;VALUE=URI:http://dir.example.com/projectors/3d.vcf
END:VRESOURCE END:VRESOURCE
8. Extended examples 8. Extended Examples
The following are some examples of the use of the properties defined The following are some examples of the use of the properties defined
in this specification. They include additional properties defined in in this specification. They include additional properties defined in
[RFC7986] which includes IMAGE. [RFC7986], which includes "IMAGE".
8.1. Example 1 8.1. Example 1
The following is an example of a VEVENT describing a concert. It
includes location information for the venue itself as well as The following is an example of a "VEVENT" describing a concert. It
includes location information for the venue itself, as well as
references to parking and restaurants. references to parking and restaurants.
BEGIN:VEVENT BEGIN:VEVENT
CREATED:20200215T145739Z CREATED:20200215T145739Z
DESCRIPTION: Piano Sonata No 3\n DESCRIPTION: Piano Sonata No 3\n
Piano Sonata No 30 Piano Sonata No 30
DTSTAMP:20200215T145739Z DTSTAMP:20200215T145739Z
DTSTART;TZID=America/New_York:20200315T150000Z DTSTART;TZID=America/New_York:20200315T150000Z
DTEND;TZID=America/New_York:20200315T163000Z DTEND;TZID=America/New_York:20200315T163000Z
LAST-MODIFIED:20200216T145739Z LAST-MODIFIED:20200216T145739Z
skipping to change at page 27, line 4 skipping to change at line 1111
STRUCTURED-DATA;VALUE=URI:http://dir.example.com/venues/big-hall.vcf STRUCTURED-DATA;VALUE=URI:http://dir.example.com/venues/big-hall.vcf
END:VLOCATION END:VLOCATION
BEGIN:VLOCATION BEGIN:VLOCATION
UID:123456-abcdef-87654321 UID:123456-abcdef-87654321
NAME:Parking for the venue NAME:Parking for the venue
STRUCTURED-DATA;VALUE=URI:http://dir.example.com/venues/parking.vcf STRUCTURED-DATA;VALUE=URI:http://dir.example.com/venues/parking.vcf
END:VLOCATION END:VLOCATION
END:VEVENT END:VEVENT
8.2. Example 2 8.2. Example 2
The following is an example of a VEVENT describing a meeting. One of
the attendees is a remote participant. The following is an example of a "VEVENT" describing a meeting. One
of the attendees is a remote participant.
BEGIN:VEVENT BEGIN:VEVENT
CREATED:20200215T145739Z CREATED:20200215T145739Z
DTSTAMP:20200215T145739Z DTSTAMP:20200215T145739Z
DTSTART;TZID=America/New_York:20200315T150000Z DTSTART;TZID=America/New_York:20200315T150000Z
DTEND;TZID=America/New_York:20200315T163000Z DTEND;TZID=America/New_York:20200315T163000Z
LAST-MODIFIED:20200216T145739Z LAST-MODIFIED:20200216T145739Z
SUMMARY:Conference planning SUMMARY:Conference planning
UID:123456 UID:123456
ORGANIZER:mailto:a@example.com ORGANIZER:mailto:a@example.com
skipping to change at page 27, line 30 skipping to change at line 1138
UID:v39lQGZvb2GFtcGxlLmNvbQ UID:v39lQGZvb2GFtcGxlLmNvbQ
STRUCTURED-DATA;VALUE=URI:http://www.example.com/people/b.vcf STRUCTURED-DATA;VALUE=URI:http://www.example.com/people/b.vcf
LOCATION:At home LOCATION:At home
END:PARTICIPANT END:PARTICIPANT
END:VEVENT END:VEVENT
9. Security Considerations 9. Security Considerations
This specification extends [RFC5545] and makes further use of This specification extends [RFC5545] and makes further use of
possibly linked data. While calendar data is not unique in this possibly linked data. While calendar data is not unique in this
regard it is worth reminding implementors of some of the dangers and regard, it is worth reminding implementors of some of the dangers and
safeguards. safeguards.
9.1. URIs 9.1. URIs
See [RFC3986] for a discussion of the security considerations See [RFC3986] for a discussion of the security considerations
relating to URIs. Because of the issues discussed there and below, relating to URIs. Because of the issues discussed there and below,
clients SHOULD NOT follow URIs and fetch content automatically, and clients SHOULD NOT follow URIs and fetch content automatically and
should only do so at the explicit request of the user. should only do so at the explicit request of the user.
Fetching remote resources carries inherent risks. Connections must Fetching remote resources carries inherent risks. Connections must
only be allowed on well known ports, using allowed protocols only be allowed on well-known ports, using allowed protocols
(generally just HTTP/HTTPS on their default ports). The URL must be (generally just HTTP/HTTPS on their default ports). The URL must be
resolved externally and not allowed to access internal resources. resolved externally and not allowed to access internal resources.
Connecting to an external source reveals IP (and therefore generally Connecting to an external source reveals IP (and therefore generally
location) information. location) information.
A maliciously constructed iCalendar object may contain a very large A maliciously constructed iCalendar object may contain a very large
number of URIs. In the case of published calendars with a large number of URIs. In the case of published calendars with a large
number of subscribers, such objects could be widely distributed. number of subscribers, such objects could be widely distributed.
Implementations should be careful to limit the automatic fetching of Implementations should be careful to limit the automatic fetching of
linked resources to reduce the risk of this being an amplification linked resources to reduce the risk of this being an amplification
vector for a denial-of-service attack. vector for a denial-of-service attack.
9.2. Malicious Content 9.2. Malicious Content
For the "STRUCTURED-DATA" property, agents need to be aware that a For the "STRUCTURED-DATA" property, agents need to be aware that a
client could attack underlying storage by sending extremely large client could attack underlying storage by sending extremely large
values and could attack processing time by uploading a recurring values and could attack processing time by uploading a recurring
event with a large number of overrides and then repeatedly adding, event with a large number of overrides and then repeatedly adding,
updating and deleting structured data. updating, and deleting structured data.
Agents should set reasonable limits on storage size and number of Agents should set reasonable limits on storage size and number of
instances and apply those constraints. Calendar protocols should instances and apply those constraints. Calendar protocols should
ensure there is a way to report on such limits being exceeded. ensure there is a way to report on such limits being exceeded.
Malicious content could be introduced into the calendar server by way Malicious content could be introduced into the calendar server by way
of the "STRUCTURED-DATA" property and propagated to many end users of the "STRUCTURED-DATA" property and propagated to many end users
via scheduling. Servers SHOULD check this property for malicious or via scheduling. Servers SHOULD check this property for malicious or
inappropriate content. Upon detecting such content, servers SHOULD inappropriate content. Upon detecting such content, servers SHOULD
remove the property, remove the property.
9.3. HTML Content 9.3. HTML Content
When processing HTML content, applications need to be aware of the When processing HTML content, applications need to be aware of the
many security and privacy issues, as described in the IANA many security and privacy issues, as described in the IANA
considerations section of [W3C.REC-html51-20171003] Considerations section of [W3C.REC-html51-20171003].
10. Privacy Considerations 10. Privacy Considerations
10.1. Tracking 10.1. Tracking
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 both by a leaks, as any network access of the URI data can be tracked both by a
network observer and by the entity hosting the remote resource. network observer and by the entity hosting the remote resource.
Clients SHOULD NOT automatically download data referenced by the URI Clients SHOULD NOT automatically download data referenced by the URI
without explicit instruction from users. without explicit instruction from users.
To help alleviate some of the concerns protocols and services could To help alleviate some of the concerns, protocols and services could
provide proxy services for downloading referenced data. provide proxy services for downloading referenced data.
10.2. Revealing Locations 10.2. Revealing Locations
The addition of location information to the new participant component The addition of location information to the new participant component
provides information about the location of participants at a given provides information about the location of participants at a given
time. This information MUST NOT be distributed to other participants time. This information MUST NOT be distributed to other participants
without those participant's express permission. Note that there may without those participant's express permission. Note that there may
be a number of participants who may be unaware of their inclusion in be a number of participants who may be unaware of their inclusion in
the data. the data.
skipping to change at page 29, line 15 skipping to change at line 1218
Agents processing and distributing calendar data must be aware that Agents processing and distributing calendar data must be aware that
it has the property of providing information about a future time when it has the property of providing information about a future time when
a given individual may be at a particular location, which could a given individual may be at a particular location, which could
enable targeted attacks against that individual. enable targeted attacks against that individual.
The same may be true of other information contained in the The same may be true of other information contained in the
participant component. In general, revealing only as much as is participant component. In general, revealing only as much as is
absolutely necessary should be the approach taken. absolutely necessary should be the approach taken.
For example, there may be some privacy considerations relating to the For example, there may be some privacy considerations relating to the
ORDER parameter, as it provides an indication of the organizer's "ORDER" parameter, as it provides an indication of the organizer's
perception of the relative importance of other participants. perception of the relative importance of other participants.
11. IANA Considerations 11. IANA Considerations
11.1. Additional iCalendar Registrations 11.1. Additional iCalendar Registrations
11.1.1. Properties 11.1.1. Properties
This document defines the following new iCalendar properties to be This document defines the following iCalendar properties that have
added to the registry defined in Section 8.2.3 of [RFC5545]: been added to the "Properties" registry defined in Section 8.2.3 of
[RFC5545]:
+--------------------+---------+----------------------+ +====================+=========+=======================+
| Property | Status | Reference | | Property | Status | Reference |
+--------------------+---------+----------------------+ +====================+=========+=======================+
| CALENDAR-ADDRESS | Current | RFCXXXX, Section 6.4 | | CALENDAR-ADDRESS | Current | RFC 9073, Section 6.4 |
| LOCATION-TYPE | Current | RFCXXXX, Section 6.1 | +--------------------+---------+-----------------------+
| PARTICIPANT-TYPE | Current | RFCXXXX, Section 6.2 | | LOCATION-TYPE | Current | RFC 9073, Section 6.1 |
| RESOURCE-TYPE | Current | RFCXXXX, Section 6.3 | +--------------------+---------+-----------------------+
| STRUCTURED-DATA | Current | RFCXXXX, Section 6.6 | | PARTICIPANT-TYPE | Current | RFC 9073, Section 6.2 |
| STYLED-DESCRIPTION | Current | RFCXXXX, Section 6.5 | +--------------------+---------+-----------------------+
+--------------------+---------+----------------------+ | RESOURCE-TYPE | Current | RFC 9073, Section 6.3 |
+--------------------+---------+-----------------------+
| STRUCTURED-DATA | Current | RFC 9073, Section 6.6 |
+--------------------+---------+-----------------------+
| STYLED-DESCRIPTION | Current | RFC 9073, Section 6.5 |
+--------------------+---------+-----------------------+
Table 1: Additions to the Properties Registry
11.1.2. Parameters 11.1.2. Parameters
This document defines the following new iCalendar property parameters This document defines the following iCalendar property parameters
to be added to the registry defined in Section 8.2.4 of [RFC5545]: that have been added to the "Parameters" registry defined in
Section 8.2.4 of [RFC5545]:
+--------------------+---------+----------------------+ +===========+=========+=======================+
| Property Parameter | Status | Reference | | Parameter | Status | Reference |
+--------------------+---------+----------------------+ +===========+=========+=======================+
| ORDER | Current | RFCXXXX, Section 5.1 | | ORDER | Current | RFC 9073, Section 5.1 |
| SCHEMA | Current | RFCXXXX, Section 5.2 | +-----------+---------+-----------------------+
+--------------------+---------+----------------------+ | SCHEMA | Current | RFC 9073, Section 5.2 |
+-----------+---------+-----------------------+
| DERIVED | Current | RFC 9073, Section 5.3 |
+-----------+---------+-----------------------+
Table 2: Additions to the Parameters Registry
11.1.3. Components 11.1.3. Components
This document defines the following new iCalendar components to be This document defines the following iCalendar components that have
added to the registry defined in Section 8.3.1 of [RFC5545]: been added to the "Components" registry defined in Section 8.3.1 of
[RFC5545]:
+-------------+---------+----------------------+ +=============+=========+=======================+
| Component | Status | Reference | | Component | Status | Reference |
+-------------+---------+----------------------+ +=============+=========+=======================+
| PARTICIPANT | Current | RFCXXXX, Section 7.1 | | PARTICIPANT | Current | RFC 9073, Section 7.1 |
| VLOCATION | Current | RFCXXXX, Section 7.2 | +-------------+---------+-----------------------+
| VRESOURCE | Current | RFCXXXX, Section 7.3 | | VLOCATION | Current | RFC 9073, Section 7.2 |
+-------------+---------+----------------------+ +-------------+---------+-----------------------+
| VRESOURCE | Current | RFC 9073, Section 7.3 |
+-------------+---------+-----------------------+
11.2. New Registration Tables Table 3: Additions to the Components Registry
11.2. Participant Types and Resource Types Registries
This section defines new registration tables for PARTICIPANT-TYPE and This section defines new registration tables for PARTICIPANT-TYPE and
RESOURCE-TYPE values. These tables are updated using the same RESOURCE-TYPE values. These tables are updated using the same
approaches laid down in Section 8.2.1 of [RFC5545] approaches laid down in Section 8.2.1 of [RFC5545].
This document creates new IANA registries for participant and This document creates new IANA registries for participant and
resource types. IANA will maintain these registries and, following resource types. IANA will maintain these registries and, following
the policies outlined in [RFC8126], new tokens are assigned after the policies outlined in [RFC8126], new tokens are assigned after
Expert Review. The Expert Reviewer will generally consult the IETF Expert Review. The Expert Reviewer will generally consult the IETF
GeoPRIV working group mailing list or its designated successor. GEOPRIV Working Group mailing list or its designated successor.
Updates or deletions of tokens from the registration follow the same Updates or deletions of tokens from the registration follow the same
procedures. The expert review should be guided by a few common sense procedures. The Expert Review should be guided by a few common-sense
considerations. For example, tokens should not be specific to a considerations. For example, tokens should not be specific to a
country, region, organization, or company; they should be well- country, region, organization, or company; they should be well
defined and widely recognized. The expert's support of IANA will defined and widely recognized. The Expert's support of IANA will
include providing IANA with the new token(s) when the update is include providing IANA with the new token(s) when the update is
provided only in the form of a schema, and providing IANA with the provided only in the form of a schema and providing IANA with the new
new schema element(s) when the update is provided only in the form of schema element(s) when the update is provided only in the form of a
a token. To ensure widespread usability across protocols, tokens token. To ensure widespread usability across protocols, tokens MUST
MUST follow the character set restrictions for XML Names [3]. Each follow the character set restrictions for XML Names
registration must include the name of the token and a brief [W3C.REC-xml-20040204]. Each registration must include the name of
description similar to the ones offered herein for the initial the token and a brief description similar to the ones offered herein
registrations contained this document: for the initial registrations contained this document.
11.2.1. Participant Types 11.2.1. Participant Types
The following table has been used to initialize the participant types +===================+=========+=======================+
registry. | Participant Type | Status | Reference |
+===================+=========+=======================+
| ACTIVE | Current | RFC 9073, Section 6.2 |
+-------------------+---------+-----------------------+
| INACTIVE | Current | RFC 9073, Section 6.2 |
+-------------------+---------+-----------------------+
| SPONSOR | Current | RFC 9073, Section 6.2 |
+-------------------+---------+-----------------------+
| CONTACT | Current | RFC 9073, Section 6.2 |
+-------------------+---------+-----------------------+
| BOOKING-CONTACT | Current | RFC 9073, Section 6.2 |
+-------------------+---------+-----------------------+
| EMERGENCY-CONTACT | Current | RFC 9073, Section 6.2 |
+-------------------+---------+-----------------------+
| PUBLICITY-CONTACT | Current | RFC 9073, Section 6.2 |
+-------------------+---------+-----------------------+
| PLANNER-CONTACT | Current | RFC 9073, Section 6.2 |
+-------------------+---------+-----------------------+
| PERFORMER | Current | RFC 9073, Section 6.2 |
+-------------------+---------+-----------------------+
| SPEAKER | Current | RFC 9073, Section 6.2 |
+-------------------+---------+-----------------------+
+-------------------+---------+----------------------+ Table 4: Initial Contents of the Participant Types
| Participant Type | Status | Reference | Registry
+-------------------+---------+----------------------+
| ACTIVE | Current | RFCXXXX, Section 6.2 |
| INACTIVE | Current | RFCXXXX, Section 6.2 |
| SPONSOR | Current | RFCXXXX, Section 6.2 |
| CONTACT | Current | RFCXXXX, Section 6.2 |
| BOOKING-CONTACT | Current | RFCXXXX, Section 6.2 |
| EMERGENCY-CONTACT | Current | RFCXXXX, Section 6.2 |
| PUBLICITY-CONTACT | Current | RFCXXXX, Section 6.2 |
| PLANNER-CONTACT | Current | RFCXXXX, Section 6.2 |
| PERFORMER | Current | RFCXXXX, Section 6.2 |
| SPEAKER | Current | RFCXXXX, Section 6.2 |
+-------------------+---------+----------------------+
11.2.2. Resource Types 11.2.2. Resource Types
The following table has been used to initialize the resource types +=========================+=========+=======================+
registry. | Resource Type | Status | Reference |
+=========================+=========+=======================+
+-------------------------+---------+----------------------+ | PROJECTOR | Current | RFC 9073, Section 6.3 |
| Resource Type | Status | Reference | +-------------------------+---------+-----------------------+
+-------------------------+---------+----------------------+ | ROOM | Current | RFC 9073, Section 6.3 |
| PROJECTOR | Current | RFCXXXX, Section 6.3 | +-------------------------+---------+-----------------------+
| ROOM | Current | RFCXXXX, Section 6.3 | | REMOTE-CONFERENCE-AUDIO | Current | RFC 9073, Section 6.3 |
| REMOTE-CONFERENCE-AUDIO | Current | RFCXXXX, Section 6.3 | +-------------------------+---------+-----------------------+
| REMOTE-CONFERENCE-VIDEO | Current | RFCXXXX, Section 6.3 | | REMOTE-CONFERENCE-VIDEO | Current | RFC 9073, Section 6.3 |
+-------------------------+---------+----------------------+ +-------------------------+---------+-----------------------+
12. Acknowledgements
The author would like to thank Chuck Norris of eventful.com for his
work which led to the development of this RFC.
The author would also like to thank the members of CalConnect, The
Calendaring and Scheduling Consortium, the Event Publication
technical committee and the following individuals for contributing
their ideas and support:
Cyrus Daboo, John Haug, Dan Mendell, Ken Murchison, Scott Otis. Table 5: Initial Contents of the Resource Types Registry
13. Normative References 12. 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,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC2426] Dawson, F. and T. Howes, "vCard MIME Directory Profile",
RFC 2426, DOI 10.17487/RFC2426, September 1998,
<https://www.rfc-editor.org/info/rfc2426>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66, Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005, RFC 3986, DOI 10.17487/RFC3986, January 2005,
<https://www.rfc-editor.org/info/rfc3986>. <https://www.rfc-editor.org/info/rfc3986>.
[RFC4589] Schulzrinne, H. and H. Tschofenig, "Location Types [RFC4589] Schulzrinne, H. and H. Tschofenig, "Location Types
Registry", RFC 4589, DOI 10.17487/RFC4589, July 2006, Registry", RFC 4589, DOI 10.17487/RFC4589, July 2006,
<https://www.rfc-editor.org/info/rfc4589>. <https://www.rfc-editor.org/info/rfc4589>.
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234,
DOI 10.17487/RFC5234, January 2008,
<https://www.rfc-editor.org/info/rfc5234>.
[RFC5545] Desruisseaux, B., Ed., "Internet Calendaring and [RFC5545] Desruisseaux, B., Ed., "Internet Calendaring and
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,
<https://www.rfc-editor.org/info/rfc5545>. <https://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,
<https://www.rfc-editor.org/info/rfc5546>. <https://www.rfc-editor.org/info/rfc5546>.
[RFC6350] Perreault, S., "vCard Format Specification", RFC 6350,
DOI 10.17487/RFC6350, August 2011,
<https://www.rfc-editor.org/info/rfc6350>.
[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>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26, Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017, RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>. <https://www.rfc-editor.org/info/rfc8126>.
[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 [RFC8259] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
Interchange Format", STD 90, RFC 8259, Interchange Format", STD 90, RFC 8259,
DOI 10.17487/RFC8259, December 2017, DOI 10.17487/RFC8259, December 2017,
<https://www.rfc-editor.org/info/rfc8259>. <https://www.rfc-editor.org/info/rfc8259>.
[W3C.REC-html51-20171003] [W3C.REC-html51-20171003]
Faulkner, S., Eicholz, A., Leithead, T., and A. Danilo, Faulkner, S., Ed., Eicholz, A., Ed., Leithead, T., Ed.,
"HTML 5.1 2nd Edition", World Wide Web Consortium and A. Danilo, Ed., "HTML 5.1 2nd Edition", World Wide Web
Recommendation REC-html51-20171003, October 2017, Consortium Recommendation REC-html51-20171003, October
<https://www.w3.org/TR/2017/REC-html51-20171003>. 2017, <https://www.w3.org/TR/2017/REC-html51-20171003>.
[W3C.REC-xml-20081126] [W3C.REC-xml-20040204]
Bray, T., Paoli, J., Sperberg-McQueen, M., Maler, E., and Sperberg-McQueen, M., Maler, E., Bray, T., Paoli, J., and
F. Yergeau, "Extensible Markup Language (XML) 1.0 (Fifth F. Yergeau, "Extensible Markup Language (XML) 1.0 (Third
Edition)", World Wide Web Consortium Recommendation REC- Edition)", World Wide Web Consortium Recommendation REC-
xml-20081126, November 2008, xml-20040204, February 2004,
<https://www.w3.org/TR/2008/REC-xml-20081126>. <https://www.w3.org/TR/2004/REC-xml-20040204>.
Appendix A. Open issues
None at the moment
Appendix B. Change log
To be deleted on publication
calext-v18 2021-??-?? MD
o Fix incorrect participant type property name in PARTICIPANT.
o Allow parameters on LOCATION-TYPE.
calext-v17 2021-01-03 MD
o Remove STRUCTURED-LOCATION property, add VLOCATION component.
o Remove STRUCTURED-RESOURCE property, add VRESOURCE component.
o Make LOCATION-TYPE multi-valued property for location.
o Make RESOURCE-TYPE multi-valued property for resource.
o Tidy up abnf.
calext-v16 2019-10-09 MD
o Make LOCTYPE multi-valued.
o Add all ATTENDEE scheduling parameters to CALENDAR-ADDRESS.
calext-v15 2019-10-08 MD
o Address various DICUSS points.
calext-v14 2019-06-11 MD
o Definition of event and social calendaring.
o Remove redefinition of SOURCE - use STRUCTURED-DATA.
calext-v13 2019-05-26 MD
o Respond to various issues.
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
o Sorted out inconsistencies in refs to 5546
calext-v08 2018-07-06 MD
o Add some text for equal ORDER values
o Switched scheduleaddress to calendaraddress in participant abnf.
Also added more properties
o Fixed PARTICIPANT abnf
calext-v04 2017-10-11 MD
o Change SCHEDULE-ADDRESS to CALENDAR-ADDRESS
o Explicitly broaden scope of SOURCE
o Add initial registry for RESTYPE and move new tables into separate
section.
o Fix PARTTYPE/PARTICIPANT-TYPE inconsistency
calext-v03 2017-10-09 MD
o Mostly typographical and other minor changes
calext-v02 2017-04-20 MD
o Add SCHEDULE-ADDRESS property
o PARTICIPANT becomes a component rather than a property. Turn many
of the former parameters into properties.
o Use existing ATTENDEE property for scheduling.
calext-v01 2017-02-18 MD
o Change ASSOCIATE back to PARTICIPANT
o PARTICIPANT becomes a component rather than a property. Turn many
of the former parameters into properties.
calext-v00 2016-08-?? MD
o Name changed - taken up by calext working group
v06 2016-06-26 MD
o Fix up abnf
o change ref to ietf from daboo
o take out label spec - use Cyrus spec
v05 2016-06-14 MD
o Remove GROUP and HASH. they can be dealt with elsewhere if desired
o Change ORDER to integer >= 1.
o Incorporate Structured-Data into this specification.
v04 2014-02-01 MD
o Added updates attribute.
o Minor typos.
o Resubmitted mostly to refresh the draft.
v03 2013-03-06 MD
o Replace PARTICIPANT with ASSOCIATE plus related changes.
o Added section showing modifications to components.
o Replace ID with GROUP and modify HASH.
o Replace TITLE param with LABEL.
o Fixed STYLED-DESCRIPTION in various ways, correct example.
v02 2012-11-02 MD
o Collapse sections with description of properties and the use cases
into a section with sub-sections.
o New section to describe relating properties.
o Remove idref and upgrade hash to have the reference
o No default value types on properties..
v01 2012-10-18 MD Many changes.
o SPONSOR and STRUCTURED-CONTACT are now in PARTICIPANT
o Add a STRUCTURED-RESOURCE property
o STYLED-DESCRIPTION to handle rich text
o Much more...
2011-01-07 [W3C.REC-xml-20081126]
Bray, T., Ed., Paoli, J., Ed., Sperberg-McQueen, M., Ed.,
Maler, E., Ed., and F. Yergeau, Ed., "Extensible Markup
Language (XML) 1.0 (Fifth Edition)", World Wide Web
Consortium Recommendation REC-xml-20081126, November 2008,
<https://www.w3.org/TR/2008/REC-xml-20081126>.
o Remove MEDIA - it's going in the Cyrus RFC Acknowledgements
o Rename EXTENDED-... to STRUCTURED-... The author would like to thank Chuck Norris of eventful.com for his
work, which led to the development of this RFC.
o Add TYPE parameter to SPONSOR The author would also like to thank the members of CalConnect: The
Calendaring and Scheduling Consortium, the Event Publication
technical committee, and the following individuals for contributing
their ideas and support:
v00 2007-10-19 MD Initial version Cyrus Daboo, John Haug, Dan Mendell, Ken Murchison, and Scott Otis.
Author's Address Author's Address
Michael Douglass Michael Douglass
Bedework Bedework
226 3rd Street 226 3rd Street
Troy, NY 12180 Troy, NY 12180
USA United States of America
Email: mdouglass@bedework.com Email: mdouglass@bedework.com
URI: http://bedework.com URI: http://bedework.com
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