Yeah, unless you've just invented a psychic server, it's impossible to restrict on the basis of gender, or race, or ideology, or anything like it. You've got to remember that no matter what restrictions you put on a forum, there will always be people who lie about who they are.
To date, there is no way to prevent that.
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I'm not likely to be around much longer. As before when I first signed up here years ago, I'm finding that after a long hiatus, and after only a few days back on here, I'm spending way too much time here again already. So I'm requesting my account be locked, banned or whatever. It's just time. Until then, well, I dunno...