I am actually rather shocked that it seems that MARC-XML, MODS, 
MARC21-binary, do not have registered Internet Content Types (aka MIME 
types).

Am I missing something, or is this really so?

Anyone know what the process is for registering such?  Anyone want to 
help try to do that? I guess we'd probably have to talk to the standards 
organizations for each of those types, rather than doing it independently?

Jonathan