(NewsNation) — New guidelines from the International Chess Federation appear to ban trans women from participating in women’s chess tournaments for at least two years.

The guidelines from FIDE, which is short for Fédération Internationale des Échecs, the organization’s original name, include several rules and guidelines specifically for trans players. FIDE sets the rules for all international chess competitions and ranks top chess players.

Some guidelines in the rulebook apply to all trans players, like requiring players to identify as that gender outside of the chess world and asking for documentation that matches an official gender change.

But trans women are specifically prohibited from competing in the women’s category until FIDE makes a further decision on the matter, which could take up to two years. They may play in the open category, however. Trans men, on the other hand, do not appear to be prohibited from playing in the men’s category.

The issue of trans women in sports has been controversial in recent years, with opponents arguing that being assigned male at birth has physical advantages over cisgender women. Those who support allowing trans women to participate in women’s sports note that hormone therapy removes those advantages.

But chess is not a physical sport, and FIDE’s guidelines appear to suggest that one’s assigned gender at birth also impacts the brain and that cisgender men hold an intellectual advantage over others.

FIDE also offers inconsistent guidelines when it comes to titles. Male-to-female trans players are allowed to keep any titles they earned before transitioning, while female-to-male trans players must relinquish any titles earned before their gender change.

NewsNation has reached out to FIDE for comment on their policy. This story will be updated if they respond.