By this trick, you can create an empty private chat window with another chatter. The recipient will only see an empty chat window opened without any message being received. This trick can be done using these emote commands, Which do not work if the recipient's username is not written (like slap, rose). To do the trick, just open a private chat with someone and write any of emote commands. That doesn't work if recipient's username is not written (Example: /slap)