RFC - 1521

MIME (Multipurpose Internet Mail Extensions) Part One: Mechanisms for Specifying and Describing the Format of Internet Message Bodies

Original:	ftp://ftp.isi.edu/in-notes/rfc1521.txt
Authors:	N. Borenstein [Bellcore], N. Freed [Innosoft]
Date:	September 1993
Category:	Informational
This specification has been !!! obsoleted !!!

---

Obsoleted by:
RFC-2049draft	Multipurpose Internet Mail Extensions (MIME) Part Five: Conformance Criteria and Examples
RFC-2048	Multipurpose Internet Mail Extensions (MIME) Part Four: Registration Procedures (Obsoleted by RFC-4288, RFC-4289) (Updated by RFC-3023prop)
RFC-2047draft	MIME (Multipurpose Internet Mail Extensions) Part Three: Message Header Extensions for Non-ASCII Text (Updated by RFC-2184, RFC-2231prop)
RFC-2046draft	Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types (Updated by RFC-3798draft, RFC-2646)
RFC-2045draft	Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies (Updated by RFC-2184, RFC-2231prop)

Obsoletes:
RFC-1341	MIME (Multipurpose Internet Mail Extensions): Mechanisms for Specifying and Describing the Format of Internet Message Bodies (Obsoleted by RFC-1521 -> RFC-2048 -> RFC-4288; -> RFC-4289; -> RFC-2049draft; -> RFC-2047draft; -> RFC-2045draft; -> RFC-2046draft)

Updated by:
RFC-1590	Media Type Registration Procedure (Obsoleted by RFC-2048 -> RFC-4288; -> RFC-4289, RFC-2049draft, RFC-2047draft, RFC-2045draft, RFC-2046draft)

Referred by:	89 RFC
Refers to:	17 RFC

---

Status

This RFC 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" for the standardization state and status of this protocol. Distribution of this memo is unlimited.

Abstract

STD 11, RFC 822^std11(-> 2822^prop) defines a message representation protocol which specifies considerable detail about message headers, but which leaves the message content, or message body, as flat ASCII text. This document redefines the format of message bodies to allow multi-part textual and non-textual message bodies to be represented and exchanged without loss of information. This is based on earlier work documented in RFC 934 and STD 11, RFC 1049^hist, but extends and revises that work. Because RFC 822^std11(-> 2822^prop) said so little about message bodies, this document is largely orthogonal to (rather than a revision of) RFC 822^std11(-> 2822^prop).

In particular, this document is designed to provide facilities to include multiple objects in a single message, to represent body text in character sets other than US-ASCII, to represent formatted multi- font text messages, to represent non-textual material such as images and audio fragments, and generally to facilitate later extensions defining new types of Internet mail for use by cooperating mail agents.

This document does NOT extend Internet mail header fields to permit anything other than US-ASCII text data. Such extensions are the subject of a companion document [RFC-1522].

This document is a revision of RFC 1341(-> 1521(-> 2049^draft | 2048(-> 4289 | 4288) | 2047^draft | 2046^draft | 2045^draft)). Significant differences from RFC 1341(-> 1521(-> 2049^draft | 2048(-> 4289 | 4288) | 2047^draft | 2046^draft | 2045^draft)) are summarized in Appendix H.

---