[OpenID] host-meta and "acct:"

[SitG Admin]

>If an application or protocol wants to define some other mechanism 
>to identify the resource an XRD is about in the absence of a 
><Subject> element, they are free to do so.  In fact, they are 
>encouraged to so.
>We left it undefined intentionally because there is no one right 
>answer... it depends on your application, your security and trust 
>requirements, and any number of other factors.

By not saying that the resource identifier is in scope for XRD files, 
they become even more flexible - we can define, for our own use(s), 
other elements (besides Subject) in the XRD file, *or* define it 
outside the XRD file. It's like the working group has taken a step 
back and said "IF you want to do it in the XRD file, here's the 
*suggested* name."

-Shade