37 C.F.R. § 2.46 Principal Register.
Title 37 - Patents, Trademarks, and Copyrights
All applications will be treated as seeking registration on the Principal Register unless otherwise stated in the application. Service marks, collective marks, and certification marks, registrable in accordance with the applicable provisions of section 2 of the Act, are registered on the Principal Register.
Title 37: Patents, Trademarks, and Copyrights
PART 2—RULES OF PRACTICE IN TRADEMARK CASES
The Written Application
§ 2.46 Principal Register.
