Whether a character identifies as male or female, as the short and simple description that'll serve for most people. Now, for the longer version, each of the five great houses and the societies that have formed under the feudal system of Arvum have different takes on sexuality and gender identity. Thrax is far and away the most hardline in terms of rigid societal control, but even they tend to be fairly permissive of their commoners. Nobles, on the other hand, for every great house can largely expect arranged marriages with the intention of furthering dynastic bloodlines, with all the lack of understanding that might imply and creating more than a few extraordinarily unhappy loveless marriages. It should be noted outside of Thrax, there's effectively no gender specific roles in the Compact, and even in Thrax it's downplayed due to more recent societal changes. For transgender or homosexual characters, if they are nobles, they will likely face tremendous pressure to marry and produce children even if a match is completely incompatible with them sexually, as noble marriage is seen as an obligation and duty, but there's not any thematic judgment about their lovers before marriage, with safe and reliable contraception being a thing. There is no historical foundation of Arxian religion or society that would paint homosexuality or being transgender as morally wrong, and that implication would be completely alien.