Network Working Group N. FREED
Request for Comments: 2045 Innosoft
Obsoletes: 1521, 1522, 1590 N. Borenstein
Category: Standards TRACK FIRTVIRTUAL
November 1996
Multi-Use Internet Mail Extension (Multi-Used Internet Save Extension Protocol (MIME))
Part 1: Internet Information Form of INTERNET
(RFC2045 - Multipurpose Internet Mail Extensions (MIME)
Part Once: Format of Internet Message Bodies
The state of this memo
This document describes an Internet standard tracking protocol, which requires further discussion and recommendations to improve. Please refer to the latest version of the Internet Formal Protocol Standard (STD1) to get the standardization and status of this protocol. The release of this memo is not restricted.
Summary
STD11, RFC 882 defines a information representation protocol that specifies the details of the US-ASCII message header, and specifies the message content (Message Body) for US-ASCII text format. . This series of documents are commonly referred to as MIME (MultiPurpose Internet Mail Extensions), redefining a series of information formats allowing the following content:
(1) Non-US-ASCII character set text message (Message Body)
(2) Extension of non-text messages in different formats
(3) Multi-part yield (Message Body)
(4) Text header of non-US-ASCII character set
This set of documents are based on earlier document RFC934, STD 11, and RFC1049, but expand and correct them. Since the RFC822 is too small to the Message Body, the correlation between the document and the RFC822 is not large (not a modified RFC822).
This document illustrates a variety of headers for describing MIME messages; the second document RFC 2046 defines the overall structure of the MIME media type system and defines the initial set of media types; the third document is RFC 2047, which expands RFC822, allows non-US-ASCII text to occur in the Internet mail header; the fourth document RFC2048 describes the different IANA registration processes of the MIME-related program; the fifth is also the last document RFC 2049 describes the MIME consistency standard, and it provides Some explanatory examples about the MIME message format, as well as "Acknowledrance" and "Reference Book".
These documents are RFC1521, RFC1522 and RFC1590 revised, while three RFCs are also revised in RFC1341 and 1342. The appendix in RFC2049 describes the different and variations of previous versions.
table of Contents
Introduction ... 3
2. Define, agreed, and general BNF grammar ... 4
2.1 CRLF. 5
2.2 Character Set ... 5
2.3 Message. 5
2.4 Entity ... 6
2.5 Some main body (Body Part) ... 6
2.6 main body (body) ... 6
2.7 7-bit data (7bit Data) ... 62.8 8-bit data (8bit data) ... 6
2.9 Binary Data (Binary Data) ... 7
2.10 lines (LINES) 7
3. Mime header field (MIME Header Fields) ... 7
4. MIME-VERSION header field ... 8
5. Content-Type header field ... 9
5.1 Syntax of the Content-Type header ... 10
5.2 default value for Content-Type ... 12
6. Content-Transfer-Encoding header ... 12
6.1 Content-Transfer-Encoding Sentence ... 12
6.2 Content-Transfer-Encoding Semiology ... 13
6.3 New Content-Transfer-Encoding. 14
6.4 Explanation and Use ... 14
6.5 Code Conversion ... 16
6.6 Specification Coding Model ... 16
6.7 quoted-printable encoding ... 16
6.8 Base64 Content-Transfer-Encoding. 20
7. Content-ID header field ... 21
8. Content-description header field ... 22
9. Additional MIME headers ... 22
10. Abstract ... 22
11. Safety considerations ... 23
12. Author address ... 23
Appendix A: Collected Syntax ... 24
