Pre-Orders
If you want to keep track of items Pre-ordered then just add location Pre-Order" (or whatever you want to call these items) when adding the item. You can then see all your pre-ordered items in Collection Management -
Then when the item arrives change the location.
Trades-in-Transit
If you trade and want to keep track of items send to you just add location "In Transfer" (or whatever you want to call these items) when adding the item. You can then see all your in transfer in Collection Management -