For posting:
- invitations to games (you can also use the New Game menu)
- information about upcoming tournaments
- discussion of games (please limit this to completed games or discussion on how a game has arrived at a certain position ... speculation on who has an advantage or the benefits of potential moves is not permitted)
- links to interesting related sites (non-promotional)
nabla: An alternative rule could be is "if a promoted piece is captured by a friendly force, it becomes a pawn again". That would prevent Queen cloning.