Knuckle tattoo

A knuckle tattoo is a tattoo on the tops of a person's fingers, between the knuckles, commonly two groups of four-letter words or one eight-letter word.^[1] It is not necessarily a prison tattoo, as sometimes believed, but remains an unpopular form of tattoo—alongside hand tattoos in general—due to the difficulty of hiding it in situations such as a formal setting where it would be seen as crass.^[2] Some people also use their knuckles to tattoo drawings and images, sometimes in groups of four, such as the four symbols of a deck of playing cards.^[3]