I just had to ban a member for 30 days for their second misgendering offense. I consider the misgendering of another member here a grave offense. It's transphobic and abusive and will not be tolerated in the slightest.
Just because you disagree with someone doesn't suddenly make them their 'birth' gender! It's bullying, plain and simple.
This goes for misgendering behind the person's back as well. Don't misgender someone in pms or mod reports. Forum staff can live without your opinion that Jack is a girl and Jane is a man. (You'd be surprised how often this happens.)
Also, do not characterize someone's behavior as masculine or effeminate either. Ok, you disagree with Jack. Does that mean he's acting 'feminine'? No, it means you're resorting to low level tactics. If you're unable to debate something without resorting to the most obvious insult, you've no business debating at all.
These offenses will result in a ban. Play it safe. Keep your opinion on someone's masculinity or femininity to yourself. If you do not know how someone identifies, use 'they' or another neutral pronoun. Or you can just ask.
