Certification marks are marks, words, names, symbols, or devices used by a person other than its owner to certify a particular quality about a product or service. The most familiar certification mark is the UL mark, which certifies that a product meets the safety standards established by Underwriters Laboratories. Other examples are the Good Housekeeping Seal of Approval, Stilton Cheese (a product from the Stilton region in England), and 100% Napa Valley (from grapes grown in the Napa Valley of northern California).