Searching by user name searches more than just the user name (Patrick has the word 'waffles' in his about section) -- is this desirable behaviour?
Even if a user matches the search criteria on a field other than user name, I think those matches should appear at the end of the results. Ideally, ordering would be, for each field starting with user name: (a) exact match, (b) starts with criteria, (c) contains criteria -- meaning the search results I've shown above would be returned in the opposite order, which, in this case at least, would have been more useful.
There are actually 5 users (4 if < 20 rep users are filtered out) at the time of writing that should match this search on user name alone. Is there another search criteria I'm missing here?
The notice "Please note that you can only add users that have already visited this chat" doesn't seem to apply (this was on a new chat room with no messages). Come to think of it, this may explain the previous point -- are these the only users out of the five who have visited chat? If so, maybe the message can be tweaked slightly (i.e., remove the word 'this') to make sense in this context.