You CAN use application/xml for any XML, but it's often useful to have a 
specific type for your specific content, so the user-agent can know what 
to do with it.  The convention is to include "+xml" on the end, so if 
the user agent doens't know your specific format, it can fall back to 
treating it as generic XML.

For instance:

application/rss+xml
application/atom+xml
application/rdf+xml

And dozens more you can see at:
http://www.iana.org/assignments/media-types/application/   (search for 
"+xml").

Thanks to Mark and Ross Singer for pointing out application/marc already 
exists. (and is on that list above).  Awesome.

I'm still feeling the need for application/marc+xml, and 
application/mods+xml

Jonathan

Ethan Gruber wrote:
> Correct me if I'm wrong, but wouldn't the mime type for MARC-XML and MODS be
> application/xml, like every other xml file?  As for MARC-binary, I can't
> say.  I don't have any of those files handy.
>
> Ethan
>
> On Wed, Feb 4, 2009 at 10:47 AM, Jonathan Rochkind <[log in to unmask]> wrote:
>
>   
>> 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
>>
>>     
>
>