Re: content negotiation

["Roy T. Fielding" <fi...@avron.ICS.UCI.EDU>]

rst writes:

> NB I'm not sure whether the right thing for language is to handle it
> as a separate header in the extended format, or simply to have it as a
> lang= parameter in the mapped MIME types; the answer is presumably in
> the MIME RFCs.  Roy, any thoughts?

It's in the latest HTTP/1.0 spec -- Accept-Language and Content-Language.
The only thing that appears in a Content-type is a ;vary="lang" if 
variants exist at that URL with different Content-Language values.

> Unresolved issues here are how to specify matches to the User-agent:
> header (initial substrings to match?  Full regex's --- and using whose
> library if so?  Something else?)

That is a nontrivial problem and generally only handled within scripts.
I would avoid it like the plague (for now).

......Roy