RFC 1049 (rfc1049) - Page 1 of 8
Content-type header field for Internet messages
Alternative Format: Original Text Document
Network Working Group M. Sirbu
Request for Comments: 1049 CMU
March 1988
A CONTENT-TYPE HEADER FIELD FOR INTERNET MESSAGES
STATUS OF THIS MEMO
This RFC suggests proposed additions to the Internet Mail Protocol,
RFC-822, for the Internet community, and requests discussion and
suggestions for improvements. Distribution of this memo is
unlimited.
ABSTRACT
A standardized Content-type field allows mail reading systems to
automatically identify the type of a structured message body and to
process it for display accordingly. The structured message body must
still conform to the RFC-822 requirements concerning allowable
characters. A mail reading system need not take any specific action
upon receiving a message with a valid Content-Type header field. The
ability to recognize this field and invoke the appropriate display
process accordingly will, however, improve the readability of
messages, and allow the exchange of messages containing mathematical
symbols, or foreign language characters.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 1
2. Problems with Structured Messages . . . . . . . . . . . . . . . 3
3. The Content-type Header Field . . . . . . . . . . . . . . . . . 5
3.1. Type Values . . . . . . . . . . . . . . . . . . . . . . 5
3.2. Version Number . . . . . . . . . . . . . . . . . . . . . 6
3.3. Resource Reference . . . . . . . . . . . . . . . . . . . 6
3.4. Comment. . . . . . . . . . . . . . . . . . . . . . . . . 7
4. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
As defined in RFC-822, [2], an electronic mail message consists of a
number of defined header fields, some containing structured
information (e.g., date, addresses), and a message body consisting of
an unstructured string of ASCII characters.
The success of the Internet mail system has led to a desire to use
the mail system for sending around information with a greater degree
of structure, while remaining within the constraints imposed by the
limited character set. A prime example is the use of mail to send a
Sirbu