I agree with Valdis' summary of the situation.
If you start using application/iotp-xml, and application/foo-xml,
and application/frobozz-xml, until the recipient updates his table,
he gets punted ALL the way back to application/octet-stream.
That's a phone call to our help desk ...
So if IOTP needs its own "application/" type, so be it.
If it can be properly routed with "application/xml", better!
But please DON'T clutter the space with foo-xml or xml-foo.
--
Rick Troth at La Casita, Houston, Texas, USA