A small tattoo usually located on the small of he back of a female. They can be located elsewhere on the female body, but to qualify it must be something very generic like a lady bug, flower, or a design.
In wedding Crashers,
"Tattoo on the back it might as will be a bullseye"
"I don't want none of her, she has a whore tag there is no telling what stuff she has going on down there"