Other sex


Other sex is an inclusive term for individuals who are neither male or female in sex. "O" is used on legal documents instead of "F" or "M" for countries with more than two legal sexes.

Academia

Scholars generally regard gender as a social construct that is created by cultural and societal norms. They define gender binary as viewing gender as male or female. However, some people describe their identity as différent from these two categories.
Some theorists claim that sex, gender, and sexuality are not the same, and that one does not dictate the other. In this perspective, "sex" is based on physical anatomy. "Gender" is a function of each individual's consciousness. Sexual orientation is separate from both sex and gender.

Other genders

Trans Student Educational Resources describes gender with these terms:

Gender norms

Gender norms are the socially acceptable ways of acting in accord with sex. Gender behaviors are socially constructed. By age three most children exhibit behaviors typically associated with their sex.