Network Working Group P. Resnick
Request for Comments: 1896 QUALCOMM
Obsoletes: 1523, 1563 A. Walker
Category: Informational InterCon
February 1996
The text/enriched MIME Content-type
Status of this Memo
This memo provides information for the Internet community. This memo
does not specify an Internet standard of any kind. Distribution of
this memo is unlimited.
Abstract
MIME [RFC-1521] defines a format and general framework for the
representation of a wide variety of data types in Internet mail. This
document defines one particular type of MIME data, the text/enriched
MIME type. The text/enriched MIME type is intended to facilitate the
wider interoperation of simple enriched text across a wide variety of
hardware and software platforms. This document is only a minor
revision to the text/enriched MIME type that was first described in
[RFC-1523] and [RFC-1563], and is only intended to be used in the
short term until other MIME types for text formatting in Internet
mail are developed and deployed.
The text/enriched MIME type
In order to promote the wider interoperability of simple formatted
text, this document defines an extremely simple subtype of the MIME
content-type "text", the "text/enriched" subtype. The content-type
line for this type may have one optional parameter, the "charset"
parameter, with the same values permitted for the "text/plain" MIME
content-type.
The text/enriched subtype was designed to meet the following
criteria:
1. The syntax must be extremely simple to parse, so that even
teletype-oriented mail systems can easily strip away the
formatting information and leave only the readable text.
2. The syntax must be extensible to allow for new formatting
commands that are deemed essential for some application.
RFC 1896 text/enriched MIME Content-type February 1996
3. If the character set in use is ASCII or an 8-bit ASCII superset,
then the raw form of the data must be readable enough to be
largely unobjectionable in the event that it is displayed on the
screen of the user of a non-MIME-conformant mail reader.
4. The capabilities must be extremely limited, to ensure that it can
represent no more than is likely to be representable by the
user's primary word processor. While this limits what can be
sent, it increases the likelihood that what is sent can be
properly displayed.
There are other text formatting standards which meet some of these
criteria. In particular, HTML and SGML have come into widespread use
on the Internet. However, there are two important reasons that this
document further promotes the use of text/enriched in Internet mail
over other such standards:
1. Most MIME-aware Internet mail applications are already able to
either properly format text/enriched mail or, at the very least,
are able to strip out the formatting commands and display the
readable text. The same is not true for HTML or SGML.
2. The current RFC on HTML [RFC-1866] and Internet Drafts on SGML
have many features which are not necessary for Internet mail, and
are missing a few capabilities that text/enriched already has.
For these reasons, this document is promoting the use of
text/enriched until other Internet standards come into more
widespread use. For those who will want to use HTML, Appendix B of
this document contains a very simple C program that converts
text/enriched to HTML 2.0 described in [RFC-1866].
Syntax
The syntax of "text/enriched" is very simple. It represents text in a
single character set--US-ASCII by default, although a different
character set can be specified by the use of the "charset" parameter.
(The semantics of text/enriched in non-ASCII character sets are
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