Disconnect purchase from being used in reservation

Hi, I have been trying to figure where to change the reservation handling to only reserve from inventory, but I cant find a easy way to do this. Do anyone know a short cut for this? Btw, shouldn’t there be a setup in Navision where this could be handled? I remember that when this reservation functionality was created, there was a setup table for this, but I can’t find that anylonger in 3.70A. Thank you Daniel