It means identifying as a non trad gender not trans exclusively. It can be as much as an assumption as calling someone who is flamboyant gay. I don’t hold my gender as an integral part of my identity so I’m not going to go out of my way to scream it to the world. I don’t care what people call me, people use male pronouns for me but if everyone decided to call me she/her or they/then tomorrow I wouldn’t give a fuck. It’s like back in the day when everyone expected all gays to be “flaming”.
Unless you can read minds or someone has told you calling someone cis will ALWAYS be an assumption. Not everyone wears their heart on their sleeve. Everyone can’t care about everything all the time. Hell most people have never even put a thought into their OWN gender and what that means to them! Labeling them as cis could be trapping them in a box as much as demanding a trans person identify as their “birth gender” (fucking pointless term). I thought we wanted to give people the choice to define themselves?
It doesn’t help that the only times someone someone has actually called me cis was people screaming “CIS SCUM” in everyone’s faces as they tried to get to work on a summers morning in Belfast. Online it’s used as a way of shutting people down.
Iv been called cis a few times, usually when someone is loosing an argument.
I don’t know what I am, but I know I’m not cis and I resent being labeled that because I don’t pretend to be an activist.