The MIME Multipart/Related Content-type
RFC 2387
| Document | Type |
RFC - Proposed Standard
(August 1998; Errata)
Obsoletes RFC 2112
|
|
|---|---|---|---|
| Last updated | 2020-05-06 | ||
| Stream | IETF | ||
| Formats | plain text html pdf htmlized with errata bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 2387 (Proposed Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | (None) | ||
| Send notices to | (None) | ||
Network Working Group E. Levinson
Request for Comments: 2387 August 1998
Obsoletes: 2112
Category: Standards Track
The MIME Multipart/Related Content-type
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (1998). All Rights Reserved.
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.
Multipart/Related MIME entities may contain Content-Disposition
headers that provide suggestions for the storage and display of a
body part. Multipart/Related processing takes precedence over
Content-Disposition; the interaction between them is discussed in
section 4.
Levinson Standards Track [Page 1]
RFC 2387 Multipart/Related August 1998
Responsibility for the display or processing of a Multipart/Related's
constituent entities rests with the application that handles the
compound object.
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
Start-info
Encoding considerations: Multipart content-types cannot have
encodings.
Security considerations: Depends solely on the referenced type.
Published specification: RFC-REL (this document).
Person & email address to contact for further information:
Edward Levinson
47 Clive Street
Metuchen, NJ 08840-1060
+1 908 494 1606
XIson@cnj.digex.net
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
Levinson Standards Track [Page 2]
RFC 2387 Multipart/Related August 1998
reference the other components. Within a single operating
environment the links are often file names, such links may be
represented within a MIME message using content-IDs or the value of
some other "Content-" headers.
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.
3.2. The Start Parameter
The start parameter, if given, is the content-ID of the compound
object's "root". If not present the "root" is the first body part in
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