A Request for Comments (RFC) is a type of publication from the Internet Engineering Task Force (IETF) and the Internet Society (ISOC), the principal technical development and standards-setting bodies for the Internet. An RFC is authored by engineers and computer scientists in the form of a memorandum describing methods, behaviors, research, or innovations applicable to the working of the Internet and Internet-connected systems. It is submitted either for peer review or simply to convey new concepts, information, or (occasionally) engineering humor. Read more on Wikipedia...
RFC 2046 Media Types November 1996
A. Collected Grammar .................................... 43
The first document in this set, RFC 2045, defines a number of header
fields, including Content-Type. The Content-Type field is used to
specify the nature of the data in the body of a MIME entity, by
giving media type and subtype identifiers, and by providing auxiliary
information that may be required for certain media types. After the