An accidental graffiti typo in which the artist sprays the alphabet (abcdefghijklmnoPqrstuvwxyz) on a wall or other desired surface, and goes back after the letter "Q" to put a line under the "P" after the forgetting that R comes after Q.
Guy 1: I was walking across the bridge the other day and some moron put 2 R's.
Guy 2: Whatchu mean?
Guy 1: He graffiti'd the alphabet like abcdefghijklmnoRqRstuvwxyz.
Guy 2: What a dumbass.