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Content-type header field for Internet messages (RFC1049)

IP.com Disclosure Number: IPCOM000001855D
Original Publication Date: 1988-Mar-01
Included in the Prior Art Database: 2000-Sep-12
Document File: 7 page(s) / 17K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

M.A. Sirbu: AUTHOR

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.

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 17% of the total text.

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

document with embedded TROFF formatting commands. A more

sophisticated example would be a message body encoded in a Page

Description Language (PDL) such as Postscript. In both cases, simply

mapping the ASCII characters to the screen or printer in the usual

fashion will not render the document image intended by the sender; an

additional processing step is required to produce an image of the

message text on a display device or a piece of paper.

In both of these examples, the message body contains only the legal

character set, but the content has a structure which produces some

desirable result after appropriate processing by the re...