It's in the contract

Over and over again I have people I share stories of my rentals with. You know,so they are aware that owning property isn't only about collecting money and having a big bank account. They hear these stories that sound made up. And almost every time I get, "You should have in the lease that they can't...." or "You should have in the lease that they have to pay if...." Uh huh... WELL in my lease (which by the way is very simple so even the simplest minds can read and understand without all the legal jargon) I have a section that reads PAINTING; Tenant agrees not to do ANY painting. Maybe I am wording it wrong?