§46(b)    (15 U.S.C. §1051 note)  Existing registrations under prior acts

Acts of 1881 and 1905. Registrations now existing under the Act of March 3, 1881, or the Act of February 20, 1905, shall continue in full force and effect for the unexpired terms thereof and may be renewed under the provisions of section 9 of this Act. Such registrations and the renewals thereof shall be subject to and shall be entitled to the benefits of the provisions of this Act to the same extent and with the same force and effect as though registered on the principal register established by this Act except as limited in sections 8, 12, 14, and 15 of this Act. Marks registered under the "10-year proviso" of section 5 of the Act of February 20, 1905, as amended, shall be deemed to have become distinctive of the registrant’s goods in commerce under paragraph (f) of section 2 of this Act and may be renewed under section 9 hereof as marks coming within said paragraph.

Act of 1920. Registrations now existing under the Act of March 19, 1920, shall expire 6 months after the effective date of this Act, or twenty years from the dates of their registrations, whichever date is later. Such registrations shall be subject to and entitled to the benefits of the provisions of this Act relating to marks registered on the supplemental register established by this Act, and may not be renewed unless renewal is required to support foreign registrations. In that event renewal may be effected on the supplemental register under the provisions of section 9 of this Act.

Subject to registration under this Act. Marks registered under previous Acts may, if eligible, also be registered under this Act.