Retail Trade Businesses are identified by the North American Industry Classification System (NAICS) code beginning in 44 or 45. The Retail Trade sector comprises establishments engaged in retailing merchandise, generally without transformation, and rendering services incidental to the sale of merchandise. The category includes both store and non-store retails. Retail establishments include office supply stores, computer and software stores, building materials dealers, plumbing supply stores, and electrical supply stores. Catalog showrooms, gasoline stations, automotive dealers and mobile home dealers are also treated s store retailers.