Draft-002-c

From Yadis

Fallback: None. Identity servers who are not able to act on a request for this "file" will send a 404. But anyway, if we can't create such a file or rewrite the request to a valid resource we would most likely not be able to deliver the capability document with another method.

Other meta data: The relying party / identity consumer won't "see" the website located at the URL (possibly this site not even exists - bug or feature?) and therefore is not possible to extract other meta data (like a link to a FOAF/vCard file) or parse the page for interesting information for this session without an additional request. However the capability document could contain these information, too (a FOAF URL as a "service").

Filename: Which magic string to use (e.g. yadis.xml or other) is a separate item to be discussed. It should be a filename that webservers in their default configuration send as text/xml (as the capability discovery document most likely will be XRD).

Here are some possible algorithms to obtain the capabilities URL from the identity URL:

Name	Algorithm	Example
Draft-002-c-1	Regardless of the identity URL, append a magic string to the identity URL, such as _yadis.xml	http://example.com/joe/ turns into http://example.com/joe/yadis.xml http://example.com/joe turns into http://example.com/joe_yadis.xml http://example.com/joe.html turns into http://example.com/joe.html_yadis.xml http://joe.example.com/ turns into http://joe.example.com/yadis.xml
Draft-002-c-2	Magic file (such as _yadis.xml) in the same "directory" as the identity URL	http://example.com/joe/ turns into http://example.com/joe/yadis.xml http://example.com/joe turns into http://example.com/yadis.xml http://example.com/joe.html turns into http://example.com/yadis.xml http://joe.example.com/ turns into http://joe.example.com/yadis.xml