RFC 1154 (rfc1154) - Page 1 of 7
Encoding header field for internet messages
Alternative Format: Original Text Document
Network Working Group D. Robinson
Request for Comments: 1154 R. Ullmann
Prime Computer, Inc.
April 1990
Encoding Header Field for Internet Messages
1. Status of the Memo
This RFC proposes an elective experimental Encoding header field to
permit the mailing of multi-part, multi-structured messages.
The use of Encoding updates RFC 1049 (Content-Type), and is a
suggested update to RFCs 1113, 1114, and 1115 (Privacy Enhancement)
[4,7,8].
Distribution of this memo is unlimited.
2. Introduction
RFC 822 [2] defines an electronic mail message to consist of two
parts, the message header and the message body, separated by an
apparently blank line.
The Encoding header field permits the message body itself to be
further broken up into parts, each part also separated from the next
by an apparently blank line.
Thus, conceptually, a message has a header part, followed by one or
more body parts, all separated by blank lines.
Each body part has an encoding type. The default (no Encoding field
in the header) is a message body of one part of type "text".
3. The Encoding Field
The Encoding field consists of one or more subfields, separated by
commas. Each subfield corresponds to a part of the message, in the
order of that part's appearance. A subfield consists of a line
count, a keyword defining the encoding, and optional information
relevant only to the specific encoding. The line count is optional
in the last subfield.
3.1. Format of the Encoding Field
The format of the Encoding field is:
Robinson & Ullmann