Whenever you are involved with a business transaction with a forum member you are able to post an iTrader. The deal must take place in an appropriate section of the forum. You can tell if the thread is in an approrpiate section when you see an iTrader number in the upper right corner of a post. To post an iTrader all youu do is click on the iTrader number - First copy the url of the thread as you will need that to complete the iTrader.
Reps are given by clicking on the icon the looks like a scales or balance in the upper right hand corner of a post. If you look in the upper right corner of my post here you will see it just to the right of the #4