Assigning Item Number to Container Code E1: 46

Customer has item numbers which represent different size boxes (These are stocked items in 9.1) to use during the pack process which the client is using P4615/P4620.  The number of boxes to be used for each shipment is added to the sales order at order creation and printed on the pick. I see that it is possible to assign an item number to a container code to represent the empty container in P46091.  Is it possible to reduce inventory of this item number (Empty Carton) when the container code is used for packaging in P4615/P420 of the container code in