Server URL arguments

[alice at goingincircles.net]

Two questions regarding the arguments the client's browser attaches to 
the server url:
   Is it supposed to be 'is_foaf' or 'is_identity'? The spec says 
'is_foaf' but Brad's demo is adding 'is_identity'.
   Is it obvious somewhere that I'm missing that all variables are in 
the format 'openid.varname'? I didn't see this anywhere in the spec and 
it was confusing me for a few minutes.

Alice Lee