Nothing is more confussing on a forum then getting genders of members confussed. Sometimes when taken the wrong way can result into an insult when not meaning too.
I know tons of forums have the option where you choose your gender in your profile settings and then an icon appears somewhere above or below your avatar in posts and I think it would be a nice thing to have to lessen confussion.
And before going "it will result in herassment" or something, I really don't think theres any sexists on AP, atleast that I know of.