Many times we have long lead type items we custom order for specific production orders when our Engineering team has yet to finish entering the final BOM.  Is there a way to be able to firm off the sales order inquires explosion purchase orders without firming the top level production order and NOT loose markings or reservations.  If we dont' firm that top level, but firm the purchase orders the markings/reservations are no permanent and other production orders will try to steal those PO line items until such time as we do firm the top level production order.