When you get Friction burn (commonly known as carpet burn) from being raped savagely or gang raped. This is rare in consensual sex, and if you got it from that then you should invest in a new partner.
Rape burn is actually used in some court cases as evidence.
However it does commonly get mixed up with rope burn, for the places that your rapist tied you up.
Rape burn isn't the same as chafing. But should be treated as pretty much the same. with some Aloe-Vera oil or minor burn creams
Donny - And here are the photos of my rape burn that those bastards over there gave me *points to defendants*.
Prosecutor - Let the records show that the victim is identifying pictures of her inner thighs taken on the night she was violated.