Medical service marks, like other service marks and trademarks, are subject to public misuse and infringement. Such misuses are sometimes innocent and sometimes fraudulently motivated. For example, throughout the history of the Mayo Clinic, the Mayo name has been publicly appropriated by unauthorized users attempting to claim an endorsement or affiliation with the clinic. On at least two occasions, the Mayo Clinic has sued misusers. Mayo prevailed in a 1962 appeal in the Minnesota Supreme Court against a business incorporating into its name the word ''Mayo'' and selling medicinal products in the Rochester, Minnesota, area. The supreme court banned such deceptive use, finding that persons would associate the name Mayo on medically related products with the Mayo Clinic. Mayo did not prevail, however, in a 1972 federal appeal against a food company attempting to register a trademark of ''mayo'' and ''7'' for mayonnaise. The court found that purchasers would not associate the ''mayo'' on a food product with the Mayo Clinic. From 1989 to 1991, a fraudulent ''Mayo Diet Pill'' circulated in Europe, where advertisements suggested that it originated at the Mayo Clinic. Its sale was stopped only after the Mayo reputation incurred an undetermined amount of damage in Europe. Public misuse of medical service marks is likely to increase as the health-care marketplace becomes more competitive.