Gas rationing occurred during World War II in order to assist in the war effort, which had caused massive shortages of gasoline. The Office of Price Administration issued a variety of stickers and ration coupons to identify users and control the amount of gas used. These stickers had to be affixed to a car’s windshield, and indicated that particular vehicle’s gasoline need. To get your classification and ration stamps, you had to certify to a local board that you needed gas and owned no more than five tires. The 'A' sticker is the most common of the WWII gas ration stickers, and was issued to the general public and entitled the holder to four gallons a week.