(a)Issuance. If ERA determines that issuance of a priority rating for a crude oil or refined petroleum product is necessary to provide the crude oil or petroleum products needed to meet the national defense requirement established by DOD, it shall issue such a rating to DOD for delivery of specified qualities and quantities of the crude oil or refined petroleum products on or during specified delivery dates or periods. In accordance with the terms of the order, DOD may then place such priority rating on a supply order.(b)Compliance. Each person who receives a priority-rated supply order pursuant to this part shall supply the specified crude oil or petroleum products to DOD in accordance with the terms of that order.(c)ERA directives. Notwithstanding any other provisions of this part, where necessary or appropriate to promote the national defense ERA is authorized to issue a directive to a supplier of crude oil or petroleum product requiring delivery of specified qualities and quantities of such crude oil or petroleum products to DOD at or during specified delivery dates or periods.(d)Use of ratings by suppliers. No supplier who receives a priority-rated supply order or directive issued under the authority of this section may use such priority order or directive in order to obtain materials necessary to meet its supply obligations thereunder.