The notion that messages carry semistructured data is central to this book. RFC934 (January 1985, Proposed Standard for Message Encapsulation) introduces the idea of a message body that is logically divided into regions separated by an “encapsulation boundary.” This idea was elaborated in a series of MIME RFCs, from RFC1341 (June 1992, MIME (Multipurpose Internet Mail Extensions) to RFC2045 (November 1996, MIME (Multipurpose Internet Mail Extensions) Part One: Format of Internet Message Bodies).
This series spells out the basic idea of MIME: a
Content-Type: header can specify that a message
body contains structured text, image data, other application-specific
data, or a composite of these types.
The author of RFC1049 (March 1988, A Content-Type Header Field for
Internet Messages) wrote, “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.” This idea would become central not only to
mailers and newsreaders, which use the
Content-Type: header to identify and process rich
content and attachments, but also to browsers. RFC2046 (November
1996, Multipurpose Internet Mail Extensions (MIME) Part Two: Media
Types) extended and revised RFC1049.
RFC2048 (November 1996, Multipurpose Internet Mail Extensions (MIME) Part Four: Registration Procedures) describes rules and procedures for registering new MIME content types.
A series beginning with RFC1872 ...