Nebraska Governor Jim Pillen signed an executive order Wednesday defining the words male and female, regulating how state agencies apply rules relating to sex. While Pillen asserted that the order would safeguard women’s sports and safety, opponents have criticized it as an attack on transgender rights.

Called the Women’s Bill of Rights, the order states there are biological differences between males and females in athletic abilities as well as safety concerns which warrant sex-based segregation for some athletic, social and educational spaces.

Specifically, the executive order defines the terms sex, female, male, woman, girl, man, boy, mother and father for use by state agencies. According to the order:

A “female” is an individual whose biological reproductive system is developed to produce ova; a “male” is an individual whose biological reproductive system is developed to fertilize the ova of a female.

Additionally, the terms woman, mother, and girl refer to a human female, while the terms man, father and boy refer to a human male. Finally, sex refers to a person’s sex assigned at birth.

Pillen said in a statement: “As Governor, it is my duty to protect our kids and women’s athletics, which means providing single-sex spaces for women’s sports, bathrooms, and changing rooms.”

Many advocates say this executive order unjustly targets transgender people and doubles down on bans prohibiting transgender individuals from playing on sports teams that match their gender identity. Nebraska State Senator Megan Hunt responded to the order on X (Twitter). “The truth is, no executive order can erase trans people. They have always existed and always will,” she said.

Wednesday’s order mirrors similar states’ efforts to define sex and gender terms. This year, Alabama’s legislature advanced a bill and Oklahoma’s governor signed an executive order using identical definitions.