Field help (PODNUM) 

Each order has its own order number. It is used to identify it.

If the order sequence number is to be manually assigned, the user must also enter an order number. Where the order number sequence assignment is automatic, a number will be assigned at the end of the creation.

When you copy a purchase order and its order date is different from the current date, a messages suggests that you recalculate the prices and discounts according to the new order date.

This is the contract number used in the creation of the delivery requests.