(a) Except as provided by subdivision (b), and subdivisions (b), (c), and (d) of Section 13532, it is unlawful for any person to place any additional advertising matter on any advertising medium referred to in this article except:

1. (1) A description of the products offered for sale in letters or numerals not larger than the price numerals.
2. (2) Methods of sale, such as self-serve or full-serve, in letters not less than one-third the size of the price numerals.
3. (3) Words describing the type of services offered at the place of business, such as food market, carwash, tune up, and the registered trademark or trade name of the service, but not the price of the service.