Roll right trouser leg up if a chap. Dangle handbag upside down from left elbow if a lady. Upon meeting suspected fellow forumer, promptly spin thrice widdershins while reciting: snorky snorky belly and bum! Or, yunno, just say something along the lines of: hello, you from the forum? We're a pretty easy bunch to spot, by and large, just cos we're usually the biggest group in the place. (I say 'we', but I won't be there myself tonight. Hmph.)