Challengesin the menu. In the rightmost column of this table, you can see whether you have solved the challenge or not. The number left from this shows the count of all users who have solved it yet. This number is red if just a very few have solved it, and green, if many users have done so.
Private Msg’sin the menu) are there to allow you to send messages to any registered user. The interface is quite self-explaining so I don't want to do this here; you are clever enough to figure it out on your own. Important might be that if you get any new messages, you can see a corresponding hint in the menu next to the link
Private Msg’s. If the addressee of any of your messages has read it you can see this in your outbox(
readappears left from the specific message). Now I just want to explain how deleting messages works.