When your waitress is a bitch and expects a tip, you give her a scratchtuity. Thus, you black out the entire tip line on the receipt. A blending of the words "scratch" and "gratuity," in case you didn't figure that out already.
That waitress was completely and utterly rude. She made me pay for barbeque sauce, and she spat in my beverage. I am going to give her a scratchtuity.