It was really designed as a short cut for a common order type. It derives directly from the OpenPosition action. For example, the LimitBuy sets the type as long and limit for you.
In the action panel, there are "Buy", and "Limit Buy", but no "Sell" or "Limit Sell". Why is it designed like that?
I know we can always use "Open Position" to achieve all position types, but it's more comfortable if the are symmetric.