Gender identity is a large theme which can be distressing for some. While most of the world operates without overt gender, our narrator for convoluted reasons genders people--not based on their sex, but based on outdated ideas of what gendered characteristics are. This gendering is often not done with the consent of the people involved, but when he knows someone's preference and is at liberty to reveal that information he will do so.But the rest of the time can ping as "misgendering" if you're sensitive to that kind of thing (it distressed me a lot the first time through the book). The book does have characters who would count as "trans" in the modern day, and they are not discriminated against for it.