Quote from GTC:
Jerry, SuccessTrade/LowTrades and at least one other broker's "trailing stop" order works like the way linkman originally mentioned in the 1st post of the thread. You have to mention both a stop price as well as "trailing by" price. That order only trails if the price goes up (for a sell "trailing stop" order). If the price only goes down after you entered the order, the trailing never triggers. In that case, the "stop" price will be hit if the price keeps going down. On the other hand, if the price goes up a little and causing the system to start trailing, then the trailing-stop will remain effective even if the price goes down afterwards.
I wish I could have expained it so eloquently. But this exactly what I was looking for. At IB anyways.