New Properties for iCalendar (RFC 7986)

Property Name

IMAGE

Purpose

This property specifies an image associated with the calendar or a calendar component.

Value Type

URI or BINARY -- no default. The value MUST be data with a media type of "image" or refer to such data.

Property Parameters

IANA, non-standard, display, inline encoding, and value data type property parameters can be specified on this property. The format type parameter can be specified on this property and is RECOMMENDED for inline binary-encoded content information.

Conformance

This property can be specified multiple times in an iCalendar object or in "VEVENT", "VTODO", or "VJOURNAL" calendar components.

Description

This property specifies an image for an iCalendar object or a calendar component via a URI or directly with inline data that can be used by calendar user agents when presenting the calendar data to a user. Multiple properties MAY be used to specify alternative sets of images with, for example, varying media subtypes, resolutions, or sizes. When multiple properties are present, calendar user agents SHOULD display only one of them, picking one that provides the most appropriate image quality, or display none. The "DISPLAY" parameter is used to indicate the intended display mode for the image. The "ALTREP" parameter, defined in [RFC5545], can be used to provide a "clickable" image where the URI in the parameter value can be "launched" by a click on the image in the calendar user agent.

Format Definition

This property is defined by the following notation:

image      = "IMAGE" imageparam
          (
            (
              ";" "VALUE" "=" "URI"
              ":" uri
            ) /
            (
              ";" "ENCODING" "=" "BASE64"
              ";" "VALUE" "=" "BINARY"
              ":" binary
            )
          )
          CRLF

imageparam = *(
           ;
           ; The following is OPTIONAL for a URI value,
           ; RECOMMENDED for a BINARY value,
           ; and MUST NOT occur more than once.
           ;
           (";" fmttypeparam) /
           ;
           ; The following are OPTIONAL,
           ; and MUST NOT occur more than once.
           ;
           (";" altrepparam) / (";" displayparam) /
           ;
           ; The following is OPTIONAL,
           ; and MAY occur more than once.
           ;
           (";" other-param)
           ;
           )

Example

The following is an example of this property

 IMAGE;VALUE=URI;DISPLAY=BADGE;FMTTYPE=image/png:h
  ttp://example.com/images/party.png

Parameter Name

DISPLAY

Purpose

To specify different ways in which an image for a calendar or component can be displayed.

Format Definition: This property parameter is defined by the following notation:

 displayparam = "DISPLAY" "=" displayval *("," displayval)

displayval = ("BADGE" / ; image inline with the title of the ; event "GRAPHIC" / ; a full image replacement for the event ; itself "FULLSIZE" / ; an image that is used to enhance the ; event "THUMBNAIL" / ; a smaller variant of "FULLSIZE" to be ; used when space for the image is ; constrained x-name / ; Experimental type iana-token) ; Other IANA-registered type ; ; Default is BADGE

Description

This property parameter MAY be specified on "IMAGE" properties. In the absence of this parameter, the default value "BADGE" MUST be used. The value determines how a client ought to present an image supplied in iCalendar data to the user.

Values for this parameter are registered with IANA as per Section 9.3.1. New values can be added to this registry following the procedure outlined in Section 8.2.1 of [RFC5545].

Servers and clients MUST handle x-name and iana-token values they don't recognize by not displaying any image at all.

Example

 IMAGE;VALUE=URI;DISPLAY=BADGE,THUMBNAIL;FMTTYPE=image/png:https://exa
  mple.com/images/weather-cloudy.png

Property Name

CONFERENCE

Purpose

This property specifies information for accessing a conferencing system.

Value Type

URI -- no default.

Property Parameters

IANA, non-standard, feature, and label property parameters can be specified on this property.

Conformance

This property can be specified multiple times in a "VEVENT" or "VTODO" calendar component.

Description

This property specifies information for accessing a conferencing system for attendees of a meeting or task. This might be for a telephone-based conference number dial-in with access codes included (such as a tel: URI [RFC3966] or a sip: or sips: URI [RFC3261]), for a web-based video chat (such as an http: or https: URI [RFC7230]), or for an instant messaging group chat room (such as an xmpp: URI [RFC5122]). If a specific URI for a conferencing system is not available, a data: URI [RFC2397] containing a text description can be used.

A conference system can be a bidirectional communication channel or a uni-directional "broadcast feed".

The "FEATURE" property parameter is used to describe the key capabilities of the conference system to allow a client to choose the ones that give the required level of interaction from a set of multiple properties.

The "LABEL" property parameter is used to convey additional details on the use of the URI. For example, the URIs or access codes for the moderator and attendee of a teleconference system could be different, and the "LABEL" property parameter could be used to "tag" each "CONFERENCE" property to indicate which is which.

The "LANGUAGE" property parameter can be used to specify the language used for text values used with this property (as per Section 3.2.10 of [RFC5545]).

Format Definition

This property is defined by the following notation:

 conference = "CONFERENCE" confparam  ":" uri CRLF

confparam  = *(
           ;
           ; The following is REQUIRED,
           ; but MUST NOT occur more than once.
           ;
           (";" "VALUE" "=" "URI") /
           ;
           ; The following are OPTIONAL,
           ; and MUST NOT occur more than once.
           ;
           (";" featureparam) / (";" labelparam) /
           (";" languageparam ) /
           ;
           ; The following is OPTIONAL,
           ; and MAY occur more than once.
           ;
           (";" other-param)
           ;
           )

Example

The following are examples of this property

 CONFERENCE;VALUE=URI;FEATURE=PHONE,MODERATOR;
  LABEL=Moderator dial-in:tel:+1-412-555-0123,,,654321
 CONFERENCE;VALUE=URI;FEATURE=PHONE;
  LABEL=Attendee dial-in:tel:+1-412-555-0123,,,555123
 CONFERENCE;VALUE=URI;FEATURE=PHONE;
  LABEL=Attendee dial-in:tel:+1-888-555-0456,,,555123
 CONFERENCE;VALUE=URI;FEATURE=CHAT;
  LABEL=Chat room:xmpp:chat-123@conference.example.com
 CONFERENCE;VALUE=URI;FEATURE=AUDIO,VIDEO;
  LABEL=Attendee dial-in:https://chat.example.com/audio?id=123456