Responding to Mark Crispin, Ned Freed writes:
I'm not really sure what APPLICATION means. It looks like a place-holder.
AUDIO, VIDEO, and IMAGE with a subtype other than G3FAX look like place-
holders too. Do we really want G3FAX, or FAX/G3 (that is, a FAX subtype
which in turn has subtypes).
IMAGE/whatever is going to be used initially by the NETFAX people. The
current proposal there is to go with something like NETFAX/TIFF/B/NETFAX.
The G3FAX type will be eliminated.
Once we have a video working group, or a color image working group, or
whatever, I expect we'll see additional use of IMAGE that is similar to but
different from what the NETFAX people are doing.
I have been arguing on the Netfax list that we need to keep G3FAX in addition
to the Image/TIFF/Netfax subtype. The Netfax format can be any of G3, G3-2d,
G4 or uncompressed, which means it hides valuable information in the TIFF
wrapper. To simplify gateways, I'd like to be able to map X.400 fax body
parts directly. Mark's suggestion of FAX/G3 (and FAX/G4, etc.) has a lot of
As far as additional IMAGE subtypes, I currently need GIF, PICT and PostScript
for my Fax gateway.