15 U.S.C. §1052(e)(4)

15 U.S.C. §1052(e)(4), also known as Section 2(e)(4) of the Lanham Act, states that a federally registered trademark cannot be "primarily merely a surname".

In determining whether a mark is "primarily merely a surname", the US Trademark Office looks to several factors, including --

1. whether the surname is rare (see TMEP §1211.01(a)(v));
2. whether the term is the surname of anyone connected with the applicant;
3. whether the term has any recognized meaning other than as a surname (see TMEP §§1211.01(a)–1211.01(a)(vii));
4. whether it has the “look and feel” of a surname (see TMEP §1211.01(a)(vi)); and
5. whether the stylization of lettering is distinctive enough to create a separate commercial impression (see TMEP §1211.01(b)(ii)).