principal register
Principal Register. Trademarks. The list of distinctive marks approved for federal trademark registration. • The register is maintained by the U.S. Patent and Trademark Office. Only marks that are strong, distinctive, and famous are listed. 15 USCA § 1052. [Cases: Trade Regulation 151. C.J.S. Trade-Marks, Trade-Names, and Unfair Competition §§ 147, 153.]