Sorry, I was unclear. The question was more, "Does the IANA export a
periodically updated document listing all the registered MIME types, or
does one send mail to iana(_at_)isi(_dot_)edu every time one wishes to know
they currently are?". The RFC doesn't say; it just specifies the
procedure for registering new types.
I hope that the list starts appearing as part of the assigned numbers stuff:
i.e. as an RFC. However, it is not for us to mandate this. IANA gets to select
the specifics. Until the list starts appearing as an RFC or some other
mechanism is selected for its distribution I think the only way to get it
is from IANA directly.