proposal for capabilities lookup

[Peter Davis]

> I think two goals are most important for adoption:
> * Those using their own site as an identity URL must be able to add
> YADIS support without writing any code or greatly disturbing their
> existing site. (The HTML indirection case.) This implies a regular GET,
> as you mentioned.
> * In *that same request* consumers must somehow indicate that it's
> really capabilities that they are interested in, so that larger identity
> hosts like LiveJournal can remove the layer of indirection and just
> return the capabilities directly, without having to generate a rather
> costly journal page that's just going to be discarded. This is the
> purpose I was bending "Accept" for.


For those unaware, in content negotiation (Accept), A userAgent can specify
_multiple_ representations in weighted order:

HTTP_ACCEPT: application/xrid+xml;q=0.9,text/html;q=0.8,text/plain;q=0.7

Which informs the server, that the user agent wourl prefer
application/xrid+xml (this is the 'official' XRID media type, though IANA
registration is pending until the resolution spec is final).

Not sure this sways anyones thinking, but it is not a oft-used capability

=peterd