Try out our new RRULE tool for creating RRULE compatible strings.

Property Name



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.


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


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)


The following are examples of this property

  LABEL=Moderator dial-in:tel:+1-412-555-0123,,,654321
  LABEL=Attendee dial-in:tel:+1-412-555-0123,,,555123
  LABEL=Attendee dial-in:tel:+1-888-555-0456,,,555123
  LABEL=Attendee dial-in:

This document was automatically converted to XHTML using an RFC to HTML converter with the original text document at the Internet Engineering Task Force web site at .  The original text document should be referred to if there are any errors or discrepancies found in this document.

Need to test your iCalendar feeds?

The iCalendar Validator provides developers and testers a method to validate their iCalendar feeds, which can take data from either a URL, file or text snippet and compare it against the RFC 5545 specification.  We believe we have one of the best iCalendar validation tools available on the internet. More information about the validator can be found here.