Hello all and apologies if this is off topic, but not quite sure where
to ask the question.
In working on my Ruby mail generator / parser
(http://github.com/mikel/mail) I ran into this inside of 2045 part 1:
encoding := "Content-Transfer-Encoding" ":" mechanism
mechanism := "7bit" / "8bit" / "binary" /
"quoted-printable" / "base64" /
ietf-token / x-token
ietf-token := <An extension token defined by a
standards-track RFC and registered
The only IANA public list I can find is:
http://www.iana.org/assignments/transfer-encodings/ which matches the
list already defined in mechanism.
Correct. There have been no additional content transfer encodings standardized
since RFC 2045.
Is this the only list of this type?
It's the list MIME is talking about.
Or am I missing something?
The only thing you're missing is that there are a number of x- token names used
for various other CTEs. However, while such things were seen fairly regularly
back when MIME was first defined, they have mostly disppeared over time.