Is any generalized compression method free from patent constraints? How
about V.42bis? How about what the GNU compression program uses?
Two issues.
If general purposed compression is to be added to MIME, it can be added
later as a content-transfer-encoding. Note that different compression
schemes work better for binary, and 7 bit transport environments.
Second, because a compression scheme is subject to patent constraints
does not mean it cannot be used for standards track protocols. PEM is
one such example of an IETF Proposed Standard which is fundamentally
dependent on specific patents and required a license to use. See RFC
1310 and its soon to be issued follow-up document for more detail on
this subject. Note that a freely available algorithm is far superior
to a restricted one from the IETF standpoint.
Greg Vaudreuil