Because of host nation tax laws, some items are rationed in the Commissaries and Exchanges.
Gasoline is a big one.
Other rationed items include cigarettes, distilled liquor, and coffee. You will be issued a ration card. Separate cards are issued for each adult family member authorized privileges and should be more than adequate for your needs. DO NOT abuse the privilege. Using your ration card to purchase items for some not authorized privileges, except as a bona fide gift, is a violation of both military regulations and host nation tax laws.