An A card was the lowest priority of gas rationing and entitled the holder to 3 gallons of gas per week (some sources say 4, probably reflecting varying rations during the war). B cards were issued to persons essential to the war effort, like war workers, and therefore entitled the holder to more gas (some sources say 8 gallons per week). C cards were granted to those who were very essential to the war effort, such as doctors. X cards entitled the holder to unlimited supplies and was the highest priority in the system. Ministers, police, volunteer firemen and civil defense workers fell within this category. Something of a scandal erupted when 200 Congressmen received these cards. T rations were available for truckers.
Gags based on these cards would, of course, have struck a chord with movie audiences, and indeed a number of shorts did use cards. The closing gag in Falling Hare (Clampett, 1943) has the plane in which Bugs and the Gremlin are plunging to almost certain death run out of gas just before crashing, Bugs observing that you know how it is with these A cards! In Tortoise Wins By a Hare (Clampett, 1943), Bugs displays his secret weapon to beat Cecil Turtle -- and flashes A and C ration cards. Russian Rhapsody (Clampett, 1944) has a gag in which one of the Russian gremlins replaces the C sticker on the windshield of Hitlers plane with an a sticker (the lower case letter adding emphasis to the gag). An slightly exaggerated view of the number of stickers on a windshield can be seen in The Weakly Reporter (Jones, 1944), in which a windshield is covered by these stickers, forcing a motorist to use a periscope to see.
Gas rationing was also reinforced by certain slogans and policies, which also found their way into the cartoons. A national speed limit of 35 miles per hour was imposed to save fuel and tires (the closing gag in The Daffy Duckeroo (McCabe, 1942), which exhorts people to Keep It Under Forty). Posters were often seen asking Is this trip really necessary? (A question asked in Draftee Daffy (Clampett, 1945) by the little man from the draft board, by a billboard in Wagon Heels (Clampett, 1945), and somewhat ironically by Daffy Duck/Duck Twacy in The Great Piggy Bank Robbery (Clampett, 1946) just after he has fallen down a trapdoor). Baseball Bugs (Freleng, 1946) also uses the gag (after Bugs tags out a Gashouse Gorilla at the plate); the cartoon was completed in June, 1945 but not released until 1946, after gas rationing had ended. Requests not to do any unnecessary traveling were also prevalent, as noted in the closing gag in The Unruly Hare (Tashlin, 1944), and Daffy, to the father in Nasty Quacks (Tashlin, 1945).