The MIME Multipart/Related Content-type
RFC 1872
Document | Type |
RFC - Experimental
(December 1995; No errata)
Obsoleted by RFC 2112
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Author | Ed Levinson | ||
Last updated | 2013-03-02 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 1872 (Experimental) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | (None) | ||
Send notices to | (None) |
Network Working Group E. Levinson Request for Comments: 1872 Accurate Information Systems, Inc. Category: Experimental December 1995 The MIME Multipart/Related Content-type Status of this Memo This memo defines an Experimental Protocol for the Internet community. This memo does not specify an Internet standard of any kind. Discussion and suggestions for improvement are requested. Distribution of this memo is unlimited. Abstract The Multipart/Related content-type provides a common mechanism for representing objects that are aggregates of related MIME body parts. This document defines the Multipart/Related content-type and provides examples of its use. 1. Introduction Several applications of MIME, including MIME-PEM, and MIME-Macintosh and other proposals, require multiple body parts that make sense only in the aggregate. The present approach to these compound objects has been to define specific multipart subtypes for each new object. In keeping with the MIME philosophy of having one mechanism to achieve the same goal for different purposes, this document describes a single mechanism for such aggregate or compound objects. The Multipart/Related content-type addresses the MIME representation of compound objects. The object is categorized by a "type" parameter. Additional parameters are provided to indicate a specific starting body part or root and auxiliary information which may be required when unpacking or processing the object. Responsibility for the display or processing of a Multipart/Related's constituent entities rests with the application that handles the compound object. Levinson Experimental [Page 1] RFC 1872 Multipart/Related December 1995 2. Multipart/Related Registration Information The following form is copied from RFC 1590, Appendix A. To: IANA@isi.edu Subject: Registration of new Media Type content-type/subtype Media Type name: Multipart Media subtype name: Related Required parameters: Type, a media type/subtype. Optional parameters: Start, a content-id. Start-info, a string or content-id list. Encoding considerations: Multipart content-types cannot have encodings. Security considerations: Depends solely on the referenced type. Published specification: This document. Person & email address to contact for further information: Edward Levinson Accurate Information Systems, Inc. 2 Industrial Way Eatontown, NJ 07724 +1 908 389 5550 +1 908 389 5556 (fax) ELevinson@Accurate.com 3. Intended usage The Multipart/Related media type is intended for compound objects consisting of several inter-related body parts. For a Multipart/Related object, proper display cannot be achieved by individually displaying the constituent body parts. The content-type of the Multipart/Related object is specified by the type parameter. The "start" parameter, if given, points, via a content-ID, to the body part that contains the object root. The default root is the first body part within the Multipart/Related body. The relationships among the body parts of a compound object distinguishes it from other object types. These relationships are often represented by links internal to the object's components that reference the other components. Within a single operating environment the links are often file names, such links may be Levinson Experimental [Page 2] RFC 1872 Multipart/Related December 1995 represented within a MIME message using content-IDs or the value of some other "Content-" header. 3.1. The Type Parameter The type parameter must be specified and its value is the MIME media type of the root body part. It permits a MIME user agent to determine the content-type without reference to the enclosed body part. If the value of the type parameter and the root body part's content-type differ then the User Agent's behavior is undefined. Note: Constraining the "type" parameter's value to an existing media type allows the appropriate processing to be identified without creating yet another hierarchy of registered types. A possible default action would have the MIME mail User Agent (MUA) to display the "start" entity alone when it could process the media type as a basic type but not as Multipart/Related. 3.2. The Start Parameter The start parameter, if given, is the content-ID of the compoundShow full document text