[OpenID] Yahoo issue

[Kevin Turner]

On Wed, 2008-02-06 at 10:51 -0800, Allen Tom wrote:
> My understanding of Section 7.3 of the OpenID 2.0 spec is that Yadis
> discovery must be supported, and that RPs must implement Yadis
> discovery before defaulting to HTML discovery.

Implementing XRDS discovery may be a MUST, but the use of the Accept
header to do that discovery is only a SHOULD.  (according to XRI
Resolution 2.0 CD 2 section 6.3.)  I do not believe there is a reliable
way to return content "only for OpenID requests."