What are the main MIME types?
The Content-Type
header describes the type of "attachment" or enclosure, in the form:
Type/Subtype
The five standard top-level Type
s can be as follows. Some
sample Subtypes are also shown.
- text, e.g., text/plain, text/html,
text/richtext, text/enriched
- image, e.g., image/jpeg, image/gif,
image/fits
- audio, e.g., audio/basic (
.au
files), audio/x-wav, audio/x-midi, audio/x-pn-realaudio
- video, e.g. video/mpeg
- application, e.g.,
application/octet-stream (a catch-all for unknown types),
application/postscript (remember, a postscript
document can contain active parts, e.g. delete your files!),
etc.
In addition, there are two composite top-level media types:
- multipart: the message has multiple different
parts. Four sub-types are defined:
- multipart/mixed: exactly what it sounds like.
- multipart/alternative: the same thing in
different formats, e.g. plain text and HTML versions.
- multipart/parallel: different parts meant to be
viewed at the same time.
- multipart/digest: each part is essentially a
mail message.
- message: another mail message, e.g.,
message/rfc822, message/partial
(for splitting up large files), and
message/external-body for referencing something
outside the message.