He needs to make three forum posts so he can put up screenshots or attach files xD. It goes for anyone new on the forums, to prevent any spam bots.
Recently there have been many cases of people posting 3 times and saying they need to do it to log on to the server, or need to do it to be able to download the game, or they can't see their forums account settings without posting first. I'm not sure how people come to think things like that, it should only stop spam accounts.