Copied from mayhem's post:
New feature:
Users who start a topic will have the option of choosing the best reply.
eg: Topic starter asks I need a particular game.
Reply 1: I also want this game.
Reply 2: Here you go....(the game gets posted).
The topic starter can then click on the accept button on the 2nd reply. After clicking on accept, the topic gets locked and its icon gets changed to

which is also visible on the board index.
Please don't press accept if the answer not given, it locks your topic and you can't unlock it yourself.