The only reason I used merit as a determining criteria is because that's one way of determining someone being a little contributive at least towards the forum, don't you think?
It's certainly the only immediate and obvious way of determining someone's worth but still you can get there and be a relative newbie and a bit colourless.
I think it's best left to the discretion of the people issuing it and nothing else. It's their idea and they'll have the feel for who they'd like to include.