The Emacs MIME library implements handling of various elements according to a (somewhat) large number of RFCs, drafts and standards documents. This chapter lists the relevant ones. They can all be fetched from https://www.rfc-editor.org.
Internet Message Format
Netnews Article Format
Format of Internet Message Bodies
Media Types
Message Header Extensions for Non-ASCII Text
Media Type Specifications and Registration Procedures
Registration Procedures (obsoleting RFC 2048)
Conformance Criteria and Examples
MIME Parameter Value and Encoded Word Extensions: Character Sets, Languages, and Continuations
HZ—A Data Format for Exchanging Files of Arbitrarily Mixed Chinese and ASCII characters
The MIME Multipart/Related Content-type
The Multipart/Report Media Type for the Reporting of Mail System Administrative Messages
Communicating Presentation Information in Internet Messages: The Content-Disposition Header Field
The Text/Plain Format and DelSp Parameters