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Property Name



This property provides the capability to associate a document object with a calendar component.

Value Type

The default value type for this property is URI. The value type can also be set to BINARY to indicate inline binary encoded content information.

Property Parameters

IANA, non-standard, 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.


This property can be specified multiple times in a "VEVENT", "VTODO", "VJOURNAL", or "VALARM" calendar component with the exception of AUDIO alarm that only allows this property to occur once.


This property is used in "VEVENT", "VTODO", and "VJOURNAL" calendar components to associate a resource (e.g., document) with the calendar component. This property is used in "VALARM" calendar components to specify an audio sound resource or an email message attachment. This property can be specified as a URI pointing to a resource or as inline binary encoded content.

When this property is specified as inline binary encoded content, calendar 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 "application/octet-stream". Format Definition: This property is defined by the following notation:

 attach     = "ATTACH" attachparam ( ":" uri ) /
                ";" "ENCODING" "=" "BASE64"
                ";" "VALUE" "=" "BINARY"
                ":" binary

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


The following are examples of this property


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.

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