About MIME types
MIME (Multipurpose Internet Mail Extensions) is a mechanism for specifying
and describing the format of Internet message bodies. It was primarily
designed for e-mail, but MIME types are used also to identify the type of
data in the HTTP protocol, the most widely used protocol on the World Wide
Web.
For a browser like AWeb, the MIME type of a document determines whether
the file should be displayed in the browser window, or be processed by
some other program.
A MIME type consists of a type and a subtype. The
type describes the major class of data, like text or image. The
subtype is used for a subdivision of the major type into different
formats, like GIF or JPEG images.
According to RFC 1521, the following official MIME types are defined:
- TEXT/HTML
- This is a document in the HTML hypertext format. Virtually all pages
on the Web are in this format.
- TEXT/PLAIN
- This type is used for plain text documents (normally in ASCII).
- APPLICATION/OCTET-STREAM
- This describes a binary file. The file could be processed by some
application. An example of this would be an LHA archive.
- APPLICATION/POSTSCRIPT
- The document is in PostScript format.
- IMAGE/GIF
- IMAGE/JPEG
- These are images, in GIF and JPEG format.
- AUDIO/BASIC
- This type is used for audio data encoded using 8-bit ISDN mu-law [PCM].
- VIDEO/MPEG
- This is an animation in MPEG format.
In addition to these official types and subtypes, it is allowed to define
extension MIME types and subtypes. These should start with X- to
avoid collisions with future official MIME types.