Cross-Referencing a Transfer Order to a Purchase Order
Cross-referencing creates a link between the demand transfer order line at the From site and the purchase order line at the From site. The supply that the purchase order line creates is reserved for that transfer order; no other demand order can use it.
Note:  This topic 
 refers to transfer orders in the context of transferring inventory between 
 sites; however, you can also transfer inventory between warehouses in 
 the same site.
      Note:  You can cross-reference 
 to a range of purchase order lines using the Material Planner Workbench form.