text
-
subtypes: plain (just ASCII) and richtext (a simple markup extension including <bold>, <italic> etc. tags)
-
character sets can be further specified in the header value field as follows:
-
Content-type: text/plain; charset=us-ascii
-
Other charsets can be used to support other languages such as iso-8859-1 (French) or iso-2022-JP (Japanese). These charsets need to be encoded in one of two encoding modes: base64 or quoted-printable. The latter retains ASCII subset and is more natural for non-ASCII extensions.
|
image
-
Standard subtypes: gif, jpeg. Others expected.
-
base64 is a natural encoding scheme for binary media - it packs three 8-bit chars into four 7-bit chars.
|
audio
-
Standard subtype: single-channel 8KHz u-law. Others expected.
|
video
-
Standard subtype: mpeg. Others plausible.
|