[Jaysun]

OPE

POE

What's that mean, please?

[Moonman62]

Those are the scribblings of base commander Ripper from the movie Dr. Strangelove. Ripper thinks the addition of flouride to our water is a Communist conspiracy to sap and impurify our precious bodily fluids. So he orders a nuclear first strike against Russia in order to get us in nuclear combat toe to toe with the rooskies. Exchange officer Mandrake tries to figure out the recall code after Ripper shoots himself in the head. He finds a paper on Ripper's desk that has variations of OPE and POE written on it, so he correctly figures that those letters are part of the recall code.

The letters can also be seen scrawled on the bathroom wall in a scene from the movie Raising Arizona.