Here's the definition that's on our security deposit page, which doesn't get into the nitty-gritty: Normal wear and tear is a term that Wisconsin law does not define.
(3)Protein Fat-Free Percentage, Protein Fat-Free Content, PFF Percentage, PFF Content or PFF of a product means the meat protein (indigenous to the raw, unprocessed pork cut) content expressed as a percent of the non-fat portion of the finished product.
Food products that are under the jurisdiction of the FSIS, and thus subject to inspection, are those that contain more than 3% meat or 2% poultry products, with several exceptions, and egg products (liquid, frozen or dried).