Three-time Olympic swimming champion Nancy Hogshead has received the U.S. Olympians and Paralympians Association’s Dorothy Franey Langkop Ambassador Award for her advocacy on behalf of female athletes. She is also urging the WNBA to establish explicit female-only eligibility rules, arguing that clear policies should be in place before any dispute arises.

Hogshead’s petition, launched in August, had more than 21,000 verified signatures by Friday, including 520 Olympians and Paralympians, according to her. The WNBA’s collective bargaining agreement says only women may play but does not define the term or set out a transgender eligibility policy; the league says there are no immediate eligibility issues and that it is continuing discussions with players. No transgender woman has played in the WNBA.