wdiff draft-ietf-calext-eventpub-extensions-00.txt draft-ietf-calext-eventpub-extensions-01.txt

Network Working Group M. Douglass
Internet-Draft Spherical Cow Group
Updates: 5545,5546 (if approved) August 24, 2016 March 5, 2017
Intended status: Standards Track
Expires: February 25, September 6, 2017

Event Publishing Extensions to iCalendar
draft-ietf-calext-eventpub-extensions-00
draft-ietf-calext-eventpub-extensions-01

Abstract

This specification introduces a number of new iCalendar properties
and components which are of particular use for event publishers and
in social networking.

This specification also defines a new STRUCTURED-DATA property for
iCalendar (RFC 5545) [RFC5545] to allow for data that is directly pertinent to
an event or task to be included with the calendar data.

Status of This Memo

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provisions of BCP 78 and BCP 79.

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This Internet-Draft will expire on February 25, September 6, 2017.

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Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 3
1.1. Conventions Used in This Document . . . . . . . . . . . . 4
2. Components and properties . . . . . . . . . . . . . . . . . . 4
3. Typed References . . . . . . . . . . . . . . . . . . . . . . 4
2.1.
3.1. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1.1. 5
3.1.1. Piano Concert Performance . . . . . . . . . . . . . . 5
2.1.2.
3.1.2. Itineraries . . . . . . . . . . . . . . . . . . . . . 5
3.
4. Modifications to Calendar Components . . . . . . . . . . . . 5
4. 6
5. New Property Parameters . . . . . . . . . . . . . . . . . . . 6
4.1. 7
5.1. Loctype . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.2. Assoctype 7
5.2. Restype . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.3. Restype
5.3. Order . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.4. Order . 8
5.4. Schema . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.5. Schema
6. New Properties . . . . . . . . . . . . . . . . . . . . . . . 9
6.1. Participant Type . . . . . . . . . 8
5. New Properties . . . . . . . . . . . 9
6.2. Styled-Description . . . . . . . . . . . . . . . . . . . 9
5.1. Associate
6.3. Structured-Location . . . . . . . . . . . . . . . . . . . 11
6.4. Structured-Resource . . . . . 9
5.2. Styled-Description . . . . . . . . . . . . . . 13
6.5. Source . . . . . 11
5.3. Structured-Location . . . . . . . . . . . . . . . . . . . 13
5.4. Structured-Resource . 14
6.6. Structured-Data . . . . . . . . . . . . . . . . . . . 14
5.5. Structured-Data . . 16
7. New Components . . . . . . . . . . . . . . . . . . . . . 16
6. Associate Types . . 18
7.1. Participant . . . . . . . . . . . . . . . . . . . . . 17
7. . . 18
8. Participant Types . . . . . . . . . . . . . . . . . . . . . . 20
9. Extended examples . . . . . . . . . . . . . . . . . . . . . . 18
7.1. 20
9.1. Example 1 . . . . . . . . . . . . . . . . . . . . . . . . 18
8. 21
10. Security Considerations . . . . . . . . . . . . . . . . . . . 19
9. 21
11. Privacy Considerations . . . . . . . . . . . . . . . . . . . 19
10. 21
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19
10.1. 22
12.1. Property Registrations . . . . . . . . . . . . . . . . . 20
10.2. 22
12.2. Parameter Registrations . . . . . . . . . . . . . . . . 20
10.3. Associate Type 22
12.3. Component Registrations . . . . . . . . . . . . . . 20
11. . . 22
12.4. Participant Types Registry . . . . . . . . . . . . . . . 23
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 21
12. 23
14. Normative References . . . . . . . . . . . . . . . . . . . . 21 23
Appendix A. Open issues . . . . . . . . . . . . . . . . . . . . 22 24
Appendix B. Change log . . . . . . . . . . . . . . . . . . . . . 22 24
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 24 26

1. Introduction

The currently existing iCalendar standard [RFC5545] lacks useful
methods for referencing additional, external information relating to
calendar components. Additionally there is no standard way to
provide rich text descriptions or meta-data associated with the
event.

Current practice is to embed this information as links in the
description or to add x-properties.

This document defines a number of properties and components
referencing such external information that can provide additional
information about an iCalendar component. The intent is to allow
interchange of such information between applications or systems
(e.g., between clients, between client and server, and between
servers). Formats such as VCARD are likely to be most useful.

A new property is also

The following properties and components are defined to support in this
specification

Styled-Description: Supports HTML descriptions. Event publishers
typically wish to provide more and better formatted information
about the event.

Additionally this specification defines

Structured-Location: There may be a property to allow the
inclusion number of structured data within the iCalendar object itself. The
existing properties in iCalendar locations associated
with an event. This provides detailed information about the
location.

Structured-Resource: Events need resources such as rooms,
projectors, conferencing capabilities.

Structured-Data: The existing properties in iCalendar cover key
elements of events and tasks such as start time, end time,
location, summary, etc. However, different types of events often
have other specific "fields" that it is useful to include in the
calendar data. For example, an event representing an airline
flight could include the airline, flight number, departure and
arrival airport codes, check-in and gate-
closing gate-closing times etc. As
another example, a sporting event might contain information about
the type of sport, the home and away teams, the league the teams
are in, information about nearby parking, etc.

Rather than define new iCalendar properties for

Participant: Many people or groups may participate in an event.
This component provides detailed information. Such participants
may act as attendees to the variety of event
types that might occur, it would be better to leverage existing
"schemas" (or derived events) or may just
provide a reference - perhaps for such data. For example, schemas available at
https://schema.org include different event types. By using standard
schemas, interoperability can mailing lists.

1.1. Conventions Used in This Document

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

2. Components and non-calendaring systems that wish properties

Previous extensions to generate or process the
data.

This specification defines a new "STRUCTURED-DATA" iCalendar property calendaring standards have been largely
restricted to allow for direct inclusion the addition of ancillary data whose schema properties or parameters. This is
partly because iCalendar libraries had trouble handling components
nested deeper than those defined elsewhere. in [RFC5545]

In a break with this 'tradition' this specification introduces some
of these extensions as components rather than properties. This property includes parameters to clearly
identify is a
better match for the type way XML and JSON handles such structures and
allows richer definitions.

It also allows for the addition of extra properties inside the schema being used so that clients can
quickly
component and easily spot what is relevant within resolves some of the calendar data and
present that problems of trying to users or process it within the calendaring system.

iCalendar does support an "ATTACH" property which can be used to
include documents or links to documents within the calendar data.
However, that property does not allow data to be included as a "TEXT"
value (a feature that "STRUCTURED-DATA" does allow), plus attachments
are often treated as "opaque" data to be processed by some other
system rather than the calendar client. Thus the existing "ATTACH"
property is not sufficient to cover the specific needs of inclusion
of schema data. Extending the "ATTACH" property to support a new
value type would likely cause interoperability problems. Thus a new
property to support inclusion of schema data is warranted.

1.1. Conventions Used in This Document

2. Typed References

The properties defined here add detailed
information as a parameter.

3. Typed References

The properties defined here can all reference external meta-data
which may be used by applications to provide enhanced value to users.
By providing type information as parameters, clients and servers are
able to discover interesting references and make use of them, perhaps
for indexing or the presentation of additional related information
for the user.

These properties are designed to handle common use cases in event
publication. It is generally important to provide information about
the organizers of such org.bedework.util.jms.events. events. Sponsors wish to be referenced in a
prominent manner. In social calendaring it is often important to
identify the active associates participants in the event, for example a school
sports team, and the inactive associates, participants, for example the parents.

The [RFC5545] LOCATION property provides only an unstructured single
text value for specifying the location where an event (or "TODO"
item) task) will
occur. This is inadequate for use cases where structured location
information (e.g. address, region, country, postal code) is required
or preferred, and limits widespread adoption of iCalendar in those
settings.

Using STRUCTURED-LOCATION, information about a number of interesting
locations can be communicated, for example, parking, restaurants and
the venue. Servers and clients can retrieve the objects when storing
the event and use them to index by geographic location.

When a calendar client receives a calendar component it can search
the set of supplied properties looking for those of particular
interest. The TYPE and FMTTYPE parameters, if supplied, can be used
to help the selection.

2.1.

3.1. Use Cases

The main motivation for these properties has been event publication
but there are opportunities for use elsewhere. The following use
cases will describe some possible scenarios.

2.1.1.

3.1.1. Piano Concert Performance

In putting together a concert there are many associates: participants: piano
tuner, performer, stage hands etc. In addition there are sponsors
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
relate to the performance in different ways.

There may be an iTip [RFC5545] meeting request for the piano tuner
who 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 an
ASSOCIATE reference to a
PARTICIPANT component for the pianist providing a reference to vcard
information about the performer. This event would also hold
information about parking, local subway stations and the venue
itself. In addition, there will be sponsorship information for
sponsors of the event and perhaps paid sponsorship properties
essentially advertising local establishments.

2.1.2.

3.1.2. Itineraries

These properties additions also provide opportunities for the travel industry.
When booking a flight the ASSOCIATE property PARTICIPANT component can be used to
provide references to businesses at the airports and to car hire
businesses at the destination.

The embedded location information can guide the traveller at the
airport or to their final destination. The contact information can
provide detailed information about the booking agent, the airlines
and car hire companies and the hotel.

4. Modifications to Calendar Components

The following changes to the syntax defined in iCalendar [RFC5545]
are made here. New elements are defined in subsequent sections.

eventc = "BEGIN" ":" "VEVENT" CRLF
eventprop *alarmc *participantc
"END" ":" "VEVENT" CRLF

eventprop =/ *(
;
; The following are OPTIONAL,
; and MAY occur more than once.
;
styleddescription / strucloc / strucres / associate / sdataprop
;
)

todoc = "BEGIN" ":" "VTODO" CRLF
todoprop *alarmc *participantc
"END" ":" "VTODO" CRLF

todoprop =/ *(
;
; The following are OPTIONAL,
; and MAY occur more than once.
;
styleddescription / strucloc / strucres / associate / sdataprop
;
)

journalc = "BEGIN" ":" "VJOURNAL" CRLF
jourprop *participantc
"END" ":" "VJOURNAL" CRLF

jourprop =/ *(
;
; The following are OPTIONAL,
; and MAY occur more than once.
;
styleddescription / associate / sdataprop
;
)

5. New Property Parameters

This specification makes use of the LABEL property parameter which is
defined in [I-D.ietf-calext-extensions]

4.1.

5.1. Loctype

Parameter name: LOCTYPE

Purpose: To specify the type of location.

Format Definition:

This parameter is defined by the following notation:

loctypeparam = "LOCTYPE" "=" param-value

Description: This parameter MAY be specified on STRUCTURED-LOCATION
and provides a way to differentiate multiple properties. For
example, it allows event producers to provide location information
for the venue and the parking.

Values for this parameter are taken from the values defined in
[RFC4589]. New location types SHOULD be registered in the manner
laid down in that specification

4.2. Assoctype

Parameter name: ASSOCTYPE

Purpose: To specify the type of associate.

Format Definition:

This parameter is defined by the following notation:

assoctypeparam = "ASSOCTYPE" "=" param-value

Description: This parameter MAY be specified on the ASSOCIATE
property, and defines the type of association. Allowable values
are defined in Section 6.

4.3.

5.2. Restype

Parameter name: RESTYPE

Purpose: To specify the type of resource.

Format Definition:

This parameter is defined by the following notation:

restypeparam = "RESTYPE" "=" param-value

Description: This parameter MAY be specified on STRUCTURED-RESOURCE
and provides a way to differentiate multiple properties.

Values for this parameter are taken from the values defined in
[todo]. New resource types SHOULD be registered in the manner
laid down in that specification

4.4.

5.3. Order

Parameter name: ORDER

Purpose: To define ordering for the associated property.

Format Definition:

This parameter is defined by the following notation:

orderparam = "ORDER" "=" integer ;Must be greater than or equal to 1

Description: The ORDER parameter is OPTIONAL and is used to indicate
the relative ordering of the corresponding instance of a property.
Its value MUST be an integer greater than or equal to 1 that
quantifies the order. Lower values correspond to a higher level
of ordering, with 1 being the highest.

When the parameter is absent, the default MUST be to interpret the
property instance as being at the lowest level of ordering.

Note that the value of this parameter is to be interpreted only in
relation to values assigned to other corresponding instances of
the same property in the same entity. A given value, or the
absence of a value, MUST NOT be interpreted on its own.

This parameter MAY be applied to any property that allows multiple
instances.

4.5.

5.4. Schema

Parameter Name: SCHEMA

Purpose: To specify the schema used for the content of a
"STRUCTURED-DATA" property value.

Format Definition:

This parameter is defined by the following notation:

schemaparam = "SCHEMA" "=" DQUOTE uri DQUOTE

Description: This property parameter SHOULD be specified on
"STRUCTURED-DATA" properties. When present it provides
identifying information about the nature of the content of the
corresponding "STRUCTURED-DATA" property value. This can be used
to supplement the media type information provided by the "FMTTYPE"
parameter on the corresponding property.

Example:

STRUCTURED-DATA;FMTTYPE=application/ld+json;
SCHEMA="https://schema.org/FlightReservation";
ENCODING=BASE64;VALUE=BINARY:Zm9vYmFy

6. New Properties

5.1. Associate

6.1. Participant Type

Property name: ASSOCIATE PARTTYPE

Purpose: This property provides a typed reference to external
information about associates in an event or optionally a plain
text typed value.

Value type: The default value type for this To specify the type of participant.

Value type: The value type for this property is URI. TEXT. The
value type can also be set to TEXT to indicate plain text content. allowable
values are defined in Section 8.

Property Parameters: Non-standard, label, assoctype, order or format
type Non-standard parameters can be specified on
this property.

Conformance: This property MAY MUST be specified in any iCalendar within a PARTICIPANT
component.

Description: When used in a component the value of this property
points to information about an event associate. This is NOT an
attendee in a scheduling sense and the ATTENDEE property may in
fact be specified in addition. Associates defines the type of participation in
events or tasks. Participants can be individuals or
organizations, for example a soccer team, the spectators, or the
musicians.

Format Definition:

This property parameter is defined by the following notation:

associate

participanttype = "ASSOCIATE" assocparam
(
(
";" "VALUE" "=" "URI"
":" uri
) /
(
";" "VALUE" "PARTICIPANT-TYPE" "=" "TEXT"
":" text
)
)
CRLF

assocparam = *(
;
; the following are OPTIONAL
; but MUST NOT occur more than once
;
(";" fmttypeparam) /
(";" labelparam) /
(";" orderparam) /
(";" assoctypeparam) /
;
; the following is OPTIONAL
; and MAY occur more than once
;
(";" other-param)
;
)

Note: When the ORDER parameter is supplied it defines the ordering
of ASSOCIATE properties with the same value for the TYPE
parameter.

Example:

The following is an example of this property. It points to a VCARD
providing information on an event associate.

ASSOCIATE;ASSOCTYPE=PRINCIPAL_PERFORMER:
http://dir.example.com/vcard/aviolinist.vcf

Example:

The following is an example referring to a VCARD providing
information on the primary contact.

ASSOCIATE;FMTTYPE=text/vcard;
ASSOCTYPE=PRIMARY-CONTACT;LABEL=A contact:
http://dir.example.com/vcard/contacts/contact1.vcf

Example:

The following is an example of the property used to link to VCARD
information on the event planner.

ASSOCIATE;FMTTYPE=text/vcard;
ASSOCTYPE=PLANNER-CONTACT;LABEL=ClownsIsUs:
http://dir.example.com/vcard/clowns-is-us.vcf

5.2. iana-token

6.2. Styled-Description

Property name: STYLED-DESCRIPTION

Purpose: This property provides for one or more rich-text
descriptions to replace or augment that provided by the
DESCRIPTION property.

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
types can be used when defined in the future. Clients MUST ignore
any properties with value types they do not understand.

Property Parameters: IANA, non-standard, id, alternate text
representation, and language property parameters can be specified
on this property.

Conformance: The property can be specified multiple times in the
"VEVENT", "VTODO", "VJOURNAL", or "VALARM" calendar components.

Description: This property is used in the "VEVENT" and "VTODO" to
capture lengthy textual descriptions associated with the activity.
This property is used in the "VJOURNAL" calendar component to
capture one or more textual journal entries. This property is
used in the "VALARM" calendar component to capture the display
text for a DISPLAY category of alarm, and to capture the body text
for an EMAIL category of alarm.

VALUE=TEXT is used to provide rich-text variants of the plain-text
DESCRIPTION property.

VALUE=URI is used to provide a link to rich-text content which is
expected to be displayed inline as part of the event.

The intent of this property is limited to providing a styled and/
or language specific version of the DESCRIPTION property. The URL
property should be used to link to websites or other related
information.

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
resource is not given by the "FMTTYPE" parameter. If the media
type remains unknown, calendar applications SHOULD treat it as
type "text/html".

Multiple STYLED-DESCRIPTION properties may be used to provide
different formats or different language variants.

Format Definition:

This property is defined by the following notation:

styleddescription = "STYLED-DESCRIPTION" styleddescparam ":"
(
(
";" "VALUE" "=" "URI"
":" uri
) /
(
";" "VALUE" "=" "TEXT"
":" text
)
)
CRLF

styleddescparam = *(
;
; The following are OPTIONAL,
; but MUST NOT occur more than once.
;
(";" altrepparam) / (";" languageparam) /
(";" fmttypeparam) /
;
; the following is OPTIONAL
; and MAY occur more than once
;
(";" other-param)
)

Example:

The following is an example of this property. It points to an html
description.

STYLED-DESCRIPTION;VALUE=URI:http://example.org/desc001.html

5.3.

6.3. Structured-Location

Property name: STRUCTURED-LOCATION

Purpose: This property provides a typed reference to external
information about the location of an event or optionally a plain
text typed value.

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
types

Property Parameters: IANA, non-standard, label, loctype or format
type parameters can be specified on this property.

Conformance: This property MAY be specified zero or more times in
any iCalendar component.

Description: When used in a component the value of this property
provides information about the event venue or of related services
such as parking, dining, stations etc..

When a LABEL parameter is supplied the language of the label must
match that of the content and of the LANGUAGE parameter if
present.

Format Definition:

This property is defined by the following notation:

strucloc = "STRUCTURED-LOCATION" struclocparam
(
(
";" "VALUE" "=" "URI"
":" uri
) /
(
";" "VALUE" "=" "TEXT"
":" text
)
)
CRLF

struclocparam = *(
;
; the following are OPTIONAL
; but MUST NOT occur more than once
;
(";" fmttypeparam) /
(";" labelparam) /
(";" languageparam) /
(";" loctypeparam) /
;
; the following is OPTIONAL
; and MAY occur more than once
;
(";" other-param)
)

Example:

The following is an example of this property. It points to a venue.

STRUCTURED-LOCATION;LABEL="The venue":
http://dir.example.com/venues/big-hall.vcf

5.4.

6.4. Structured-Resource

Property name: STRUCTURED-RESOURCE

Purpose: This property provides a typed reference to external
information about a resource or optionally a plain text typed
value.

Value type: The default value type for this property is URI. The
value type can also be set to TEXT to indicate plain text content.

Property Parameters: IANA, non-standard, label, restype or format
type parameters can be specified on this property.

Conformance: This property MAY be specified zero or more times in
any iCalendar component.

Description: When used in a component the value of this property
provides information about resources used for the event.

When a LABEL parameter is supplied the language of the label must
match that of the content and of the LANGUAGE parameter if
present.

Format Definition:

This property is defined by the following notation:

strucres = "STRUCTURED-RESOURCE" strucresparam (":" uri) /
(
";" "VALUE" "=" "TEXT"
":" text
)
CRLF

strucresparam = *(
;
; the following are OPTIONAL
; but MUST NOT occur more than once
;
(";" fmttypeparam) /
(";" labelparam) /
(";" languageparam) /
(";" restypeparam) /
;
; the following is OPTIONAL
; and MAY occur more than once
;
(";" other-param)
)

Example:

The following is an example of this property. It refers to a
projector.

STRUCTURED-RESOURCE;restype="projector":
http://dir.example.com/projectors/3d.vcf

5.5. Structured-Data

6.5. Source

Property Name: STRUCTURED-DATA name: SOURCE

Purpose: This property specifies ancillary data associated with the
calendar component.

Value Type: TEXT

Property Parameters: IANA, non-standard, inline encoding, provides a reference to vcard information
about a participant in an event or optionally a plain text typed
value.

Value type: The default value type for this property is URI. The
value type can also be set to TEXT to indicate plain text content.

Property Parameters: Non-standard or format type parameters can be
specified on this property.

Conformance: This property MAY be appear in any iCalendar component.

Description: This property provides information about the component
in which it appears. It may provide a refernce to a vcard giving
directory information about a resource or participant.

Format Definition:

This property is defined by the following notation:

source = "SOURCE" sourceparam
(
(
";" "VALUE" "=" "URI"
":" uri
) /
(
";" "VALUE" "=" "TEXT"
":" text
)
)
CRLF

sourceparam = *(
;
; the following are OPTIONAL
; but MUST NOT occur more than once
;
(";" fmttypeparam) /
;
; the following is OPTIONAL
; and MAY occur more than once
;
(";" other-param)
;
)

Example:

The following is an example referring to a VCARD.

SOURCE;FMTTYPE=text/vcard;
http://dir.example.com/vcard/contacts/contact1.vcf

6.6. Structured-Data

Property Name: STRUCTURED-DATA

Purpose: This property specifies ancillary data associated with the
calendar component.

Value Type: TEXT

Property Parameters: IANA, non-standard, inline encoding, and value
data type property parameters can be specified on this property.
The format type and schema parameters can be specified on this
property and are RECOMMENDED for text or inline binary encoded
content information.

Conformance: This property can be specified multiple times in an
iCalendar object. Typically it would be used in "VEVENT",
"VTODO", or "VJOURNAL" calendar components.

Description: This property is used to specify ancillary data in some
structured format either directly (inline) as a "TEXT" or "BINARY"
value, or as a link via a "URI" value.

Format Definition:

Rather than define new iCalendar properties for the variety of
event types that might occur, it would be better to leverage
existing "schemas" for such data. For example, schemas available
at https://schema.org include different event types. By using
standard schemas, interoperability can be improved between
calendar clients and non-calendaring systems that wish to generate
or process the data.

This property is defined by allows the following notation: direct inclusion of ancillary data whose
schema is defined elsewhere. This property also includes
parameters to clearly identify the type of the schema being used
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 calendaring system.

iCalendar does support an "ATTACH" property which can be used to
include documents or links to documents within the calendar data.
However, that property does not allow data to be included as a
"TEXT" value (a feature that "STRUCTURED-DATA" does allow), plus
attachments are often treated as "opaque" data to be processed by
some other system rather than the calendar client. Thus the
existing "ATTACH" property is not sufficient to cover the specific
needs of inclusion of schema data. Extending the "ATTACH"
property to support a new value type would likely cause
interoperability problems. Thus a new property to support
inclusion of schema data is warranted.

Format Definition:

This property is defined by the following notation:

sdataprop = "STRUCTURED-DATA" sdataparam
(":" text) /
(
";" "ENCODING" "=" "BASE64"
";" "VALUE" "=" "BINARY"
":" binary
) /
(
";" "VALUE" "=" "URI" binary
) /
(
";" "VALUE" "=" "URI"
":" uri
)
CRLF

sdataparam = *(
;
; The following is OPTIONAL for a URI value,
; RECOMMENDED 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:

STRUCTURED-DATA;FMTTYPE=application/ld+json;
SCHEMA="https://schema.org/SportsEvent";
VALUE=TEXT:{\n
"@context": "http://schema.org"\,\n
"@type": "SportsEvent"\,\n
"homeTeam": "Pittsburgh Pirates"\,\n
"awayTeam": "San Francisco Giants"\n
}\n

7. New Components

7.1. Participant

Component name: PARTICIPANT

Purpose: This component provides information about a participant in
an event or optionally a plain text typed value.

Conformance: This component MAY be appear in any iCalendar
component.

Description: This component provides information about an
participant in an event, task or poll. A participant may be an
attendee in a scheduling sense and the ATTENDEE property may be
specified in addition (See backwards compatability issues).
Participants in events can be individuals or organizations, for
example a soccer team, the spectators, or the musicians.

The SOURCE property if present may refer to an external definition
of the participant - such as a vcard.

The URI property (def?) if present will provide a mailto: or other
address. If a related ATTENDEE proeprty is generated it will have
the same value as the URI.

Format Definition:

This property is defined by the following notation:

participantc = "BEGIN" ":" "PARTICIPANT" CRLF
partprop *alarmc
"END" ":" uri
) "PARTICIPANT" CRLF

sdataparam

partprop = *(
;
; The following is OPTIONAL for a URI value, are REQUIRED,
; RECOMMENDED for a TEXT or BINARY value, but MUST NOT occur more than once.
; and
dtstamp / participanttype /
;
; The following are OPTIONAL,
; but MUST NOT occur more than once.
;
(";" fmttypeparam)
created /
(";" schemaparam) description / last-mod / seq /
source / status / summary / url /
;
; The following is are OPTIONAL,
; and MAY occur more than once.
;
(";" other-param)
attach / categories / comment /
contact / rstatus / related /
resources / x-prop / iana-prop
;
)

Note: When the PRIORITY is supplied it defines the ordering of
PARTICIPANT components with the same value for the TYPE parameter.

Example:

The following is an example of this property:

6. Associate component. It contains a SOURCE
property which points to a VCARD providing information about the
event participant.

BEGIN:PARTICIPANT
PARTTYPE:PRINCIPAL_PERFORMER
SOURCE:http://dir.example.com/vcard/aviolinist.vcf
END:PARTICIPANT

Example:

The following is an example for the primary contact.

BEGIN: PARTICIPANT
SOURCE;FMTTYPE=text/vcard;
http://dir.example.com/vcard/contacts/contact1.vcf
PARTTYPE:PRIMARY-CONTACT
DESCRIPTION:A contact:
END:PARTICIPANT

8. Participant Types

This section describes types of association participation and provide registered
values for the ASSOCIATE property ASSOCTYPE parameter. PARTTYPE property.

ACTIVE: An associate A participant taking an active role - for example a team
member.

INACTIVE: An associate A participant taking an inactive part - for example an
audience member.

SPONSOR: A sponsor of the event. The ORDER parameter may be used
with this associate participant type to define the relative order of
multiple sponsors.

CONTACT: Contact information for the event. The ORDER parameter may
be used with this associate participant type to define the relative order of
multiple contacts.

BOOKING-CONTACT: Contact information for reservations or payment

EMERGENCY-CONTACT: Contact in case of emergency

PUBLICITY-CONTACT: Contact for publicity

PLANNER-CONTACT: Contact for the event planner or organizer

PERFORMER: A performer - for example the soloist or the accompanist.
The ORDER parameter may be used with this associate participant type to
define the relative order of multiple sponsors. performers. For example,
ORDER=1 could define the principal performer or soloist.

SPEAKER: Speaker at an event

9. Extended examples

The following are some examples of the use of the properties defined
in this specification. They include additional properties defined in
[I-D.ietf-calext-extensions] which includes IMAGE and LIVEFEED.

7.1.

9.1. Example 1

The following is an example of a VEVENT describing a concert. It
includes location information for the venue itself as well as
references to parking and restaurants.

BEGIN:VEVENT
CREATED:20101116T145739Z
DESCRIPTION: Piano Sonata No 3\n
Piano Sonata No 30
DTSTAMP:20101116T145739Z
DTSTART;TZID=America/New_York:20110315T150000Z
DTEND;TZID=America/New_York:20110315T163000Z
LAST-MODIFIED:20101116T145739Z
SUMMARY:Beethoven Piano Sonatas
UID:123456
STRUCTURED-LOCATION;LABEL="The venue":
http://dir.example.com/venues/big-hall.vcf
STRUCTURED-LOCATION;LABEL="The venue":
http://dir.example.com/venues/parking.vcf
ASSOCIATE;ASSOCTYPE=SPONSOR:http://example.com/sponsor.vcf
ASSOCIATE;ASSOCTYPE=PERFORMER:
http://www.example.com/people/johndoe.vcf
BEGIN:PARTICIPANT
PARTTYPE:SPONSOR
SOURCE:http://example.com/sponsor.vcf
END:PARTICIPANT
BEGIN:PARTICIPANT
PARTTYPE:PERFORMER:
SOURCE:http://www.example.com/people/johndoe.vcf
END:PARTICIPANT
END:VEVENT

10. Security Considerations

Applications using these properties need to be aware of the risks
entailed in using the URIs provided as values. See [RFC3986] for a
discussion of the security considerations relating to URIs.

Security considerations relating to the "ATTACH" property, as
described in [RFC5545], are applicable to the "STRUCTURED-DATA"
property.

11. Privacy Considerations

Properties with a "URI" value type can expose their users to privacy
leaks as any network access of the URI data can be tracked. Clients
SHOULD NOT automatically download data referenced by the URI without
explicit instruction from users. This specification does not
introduce any additional privacy concerns beyond those described in
[RFC5545].

10.

12. IANA Considerations
10.1.

12.1. Property Registrations

This document defines the following new iCalendar properties to be
added to the registry defined in Section 8.2.3 of [RFC5545]:

10.2.

12.2. Parameter Registrations

This document defines the following new iCalendar property parameters
to be added to the registry defined in Section 8.2.4 of [RFC5545]:

12.3. Component Registrations

This document defines the following new iCalendar components to be
added to the registry defined in Section 8.3.1 of [RFC5545]:

10.3. Associate Type Registrations
+-------------+---------+----------------------+

12.4. Participant Types Registry

The following table has been used to initialize the associate participant types
registry.

11.

13. 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 the Calendaring
and Scheduling Consortium Event Publication technical committee and
the following individuals for contributing their ideas and support:

Cyrus Daboo, John Haug, Dan Mendell, Scott Otis,

The authors would also like to thank the Calendaring and Scheduling
Consortium for advice with this specification.

12.

14. Normative References

[I-D.ietf-calext-extensions]
Daboo, C., "New Properties for iCalendar", draft-ietf-
calext-extensions-05 (work in progress), August 2016.

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.

[RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", RFC 2434,
DOI 10.17487/RFC2434, October 1998,
<http://www.rfc-editor.org/info/rfc2434>.

[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<http://www.rfc-editor.org/info/rfc3688>.

[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005,
<http://www.rfc-editor.org/info/rfc3986>.

[RFC4589] Schulzrinne, H. and H. Tschofenig, "Location Types
Registry", RFC 4589, DOI 10.17487/RFC4589, July 2006,
<http://www.rfc-editor.org/info/rfc4589>.

[RFC5545] Desruisseaux, B., Ed., "Internet Calendaring and
Scheduling Core Object Specification (iCalendar)",
RFC 5545, DOI 10.17487/RFC5545, September 2009,
<http://www.rfc-editor.org/info/rfc5545>.

[RFC5546] Daboo, C., Ed., "iCalendar Transport-Independent
Interoperability Protocol (iTIP)", RFC 5546,
DOI 10.17487/RFC5546, December 2009,
<http://www.rfc-editor.org/info/rfc5546>.

[W3C.REC-xml-20060816]
Bray, T., Paoli, J., Sperberg-McQueen, M., Maler, E., and
F. Yergeau, "Extensible Markup Language (XML) 1.0 (Fourth
Edition)", World Wide Web Consortium Recommendation REC-
xml-20060816, August 2006,
<http://www.w3.org/TR/2006/REC-xml-20060816>.

Appendix A. Open issues

restype values: Need to determine what if any registry of resource
types already exists and use that.

Appendix B. Change log

v05 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.

v05 2016-08-?? MD

o Name changed - taken up by calext working group

v05 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

o Remove MEDIA - it's going in the Cyrus RFC

o Rename EXTENDED-... to STRUCTURED-...

o Add TYPE parameter to SPONSOR

v00 2007-10-19 MD Initial version

Author's Address

Michael Douglass
Spherical Cow Group
226 3rd Street
Troy, NY 12180
USA

Email: mdouglass@sphericalcowgroup.com
URI: http://sphericalcowgroup.com