>> For issue 1, I think that we don't need an IANA registry at this point, in particular because we are not expecting extensions to this attribute. My proposal is to simply indicate that organizations that want to extend this attribute and create new tokens should use their reversed names to avoid clashes among then.
> Out of curiosity, if we don't expect extensions, do we need the extension point int he ABNF?
It is hard to determine what the future will bring. If we remove the
extensibility now, and in the future we want to create an extension, then
we will be forced to create a new SDP attribute. If we have the
extensibility in place, but not the IANA registry, we can always create
the IANA registry at a later point.
So, I am leaning towards being conservative, and allow the extensibility
of the SDP 'chatroom' attribute, without having an IANA registry at this