Section 7.4.1 URI requirement

From Yadis

In Section 7.4.1 the sentence

If a Relying Party Agent selects a Service element that contains one or more URI elements, that Relying Party Agent MUST recognize and use at least one URI element of that Service element, as specified for the service(s) identified by that Service element..

can be removed. It should be possible to define a service where defining and/or using a is optional. It also contradicts the last sentence of this section.

Done.