How is the cost retrieved in Credit Orders?

In Credit Orders (P4211), the current cost is retrieved by default, but the user can change it if the cost field is not protected.To prevent users from changing the cost in this screen, make sure that protect cost processing option is enabled (1 or 2):
FIELD DISPLAY CONTROL:                      
Enter '1' to protect or '2' to suppress    
30. Cost Fields                            1
31. Price Fields                          
In Credit Orders from History (P42025), the cost stored in Sales Order Ledger (P42199) record is retrieved, but  if the Cost Field processing option (PO#30)  is disabled in the invoked  version of Credit Order Entry (P4211) , the user can enter a different cost.