supplemental register

In United States trademark law, the Supplemental Register is the secondary register of trademarks maintained by the United States Patent and Trademark Office. It was established in 1946 by Subchapter II of the Lanham Act, for the purposes of allowing domestic registration of trademarks which do not meet all of the requirements for registration on the Principal Register, so that the holders of such a mark could register it in another country. This was necessary because under the Paris Convention for the Protection of Industrial Property, foreign registration was not permitted in the absence of domestic registration, and the trademark laws of countries outside the U.S. often have less stringent registration requirements for marks.
See more at Wikipedia.org...

secondary trademark register for the USPTO. It allows for registration of certain marks that are not eligible for registration on the Principal Register, but are capable of distinguishing an applicant’s goods or services. Marks registered on the Supplemental Register receive protection from conflicting marks and other protections, but are excluded from receiving the advantages of certain sections of the Trademark Act of 1946. The excluded sections are listed in 15 U.S.C. §1094.

If the applicant seeks registration on the Supplemental Register, the application should state that registration is requested on the Supplemental Register. If no register is specified, the Office will presume that the applicant seeks registration on the Principal Register. To register a mark on the Supplemental Register, applicants must either be using the mark or filing under Trademark Act Section 44 based on a foreign registration.

Context: Trademark