I don't have an off limits list. Instead I just eat what ever I want while trying the best I can to pursue foods that I think are better for me. That's probably roughly 80/20, sometimes better and other times worse. But I make it work.
So in reality there is no cheating for me because I'm not on a diet.
However, when I really want to try to cut fast, which I haven't done or needed to do in a while, I'll be more strict for several weeks. Even then, I'll allow some slack if I have to. With a cutting diet, if you're really doing it right, even one cheat day isn't going to hurt, so long as you aren't purposely stuffing yourself. That's actually how I did it once last year simply because I didn't have easy convenient access to the ideal foods on Sundays, so that would be my cheat day, but even on that day I'd try to watch it on the calories.