I appreciate the information.  I should have said why am I able to.  These items are not items in my inventory and since they are non-inventory part numbers, they do not create a negative inventory item.  In order for me to print accurate packing slip, meaning for non-inventory items I have purchased and received to show as to be picked, I need to invoice the sales order and then print a pick or packing slip.  Since we have more than one person in the system, I was hoping to find a way so that I wouldn't accidentally invoice something that has not been received yet.  Thank you.