A (demo) is a new character who has not yet been activated by a GM. A true (demo) is a completely new and inexperienced player, it is a good idea to help these people. Other (demo)s can be alternate characters of those who know Oberin.
It is possible to find a demo using the Orb of Seeing if they tell you their chosen name, or if they are a rogue and bump into you.
It is good for a (demo) to use /help to try to bring a GM to answer questions and possibly name them, activate their name.