Rath (plaintiff) was a German citizen who had registered his trademarks “Dr. Rath” and “Rath” for goods and services in Germany. Rath applied for registration in the United States. The trademark examiner refused the application on the grounds that the trademarks were primarily merely surnames, which are barred from registration under the Lanham Act. The Trademark Trial and Appeal Board (the Board) upheld the refusal. Rath appealed, conceding that the trademarks were primarily surnames, but alleging that under the Paris Convention, an international agreement governing foreign trademark to which the United States was a party, the marks must be accepted for registration in the United States because they had been duly registered in Germany.