R12 was a planet in the Star Wars comic series. R12 was best known for producing a unique gas, also called R12, that was the most potent refrigerant known to the galaxy. R12 gas became obselete when the planet R12 was destroyed by the Death Star.
<Han Solo> Quick, Chewie, grab a can of R12 and recharge the A/C system.
<Chewie> (unintelligible reply)