<reference xmlns='urn:xmpp:reference:0'
type='urn:xmpp:reference:mention:0'
kind='urn:xmpp:reference:mention:0#hats'
uri='https://example.com/schema/hats/cool-people'
begin='5' end='10 />
Why would there be both type and kind? These seem redundant. A "mention" of
a group/hat is a fundamentally different thing than a mention, belongs in
its own XEP, and certainly deserves it's own type or possibly own syntax.
Because room mentions don't even have a target URI
By room mentions you mean attention XEP?