http://www.rfc-editor.org/rfc/rfc2046.txt
RFC 2046: Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types, N. Freed, N. Borenstein1996-11-01T23:00:00-00:00This second document defines the general structure of the MIME media typing system and defines an initial set of media types. [STANDARDS-TRACK]