RE: [security-services] Metadata extension proposal/namespace

> if only because it establishes a convention to use when we do 
> our next extension.

Well, given that it's an XML namespace, the idea behind a generic name was
that we could add any additional extensions we adopted to it. Even the 1.1
SourceID thing if we wanted to change that.

Not saying we have to do that, but adding new top level elements to the
schema doesn't break anything.

-- Scott