token
Click on the red underlined text to get to the source
... extension-token ...
... extension-token ...
... ietf-token ...
... x-token ...
... <The two characters "X-" or "x-" followed, with no intervening white space, by any token> ...
... extension-token ...
... iana-token ...
... token ...
... token ...
...
The Content-Transfer-Encoding field's value is a single token
specifying the type of encoding, as enumerated below. Formally:
...
... ietf-token ...
... x-token ...
...
This single Content-Transfer-Encoding token actually provides two
pieces of information. It specifies what sort of encoding
...
... Implementors may, if necessary, define private Content-Transfer-
Encoding values, but must use an x-token, which is a name prefixed by
"X-", to indicate its non-standard status, e.g., "Content-Transfer-
Encoding ...
... token ...
... extension-token ...
... extension-token ...
... ietf-token ...
... x-token ...
... <A publicly-defined extension token. Tokens of this form must be registered with IANA as specified in RFC 2048(-> 4289 | 4288) ...
... <A publicly-defined extension token. Tokens of this form must be registered with IANA as specified in RFC 2048(-> 4289 | 4288).> ...
... ietf-token ...
... x-token ...
... extension-token ...
... iana-token ...
... token ...
... <The two characters "X-" or "x-" followed, with no intervening white space, by any token> ...