For the younger crowd, A/S/L? Was a typical introduction between people who were taking their chat to the next level. Like a handshake introduction in a room of crowded people where up to that point you were just throwing responses into the group discussion. This was in the days of IRC and Yahoo! Chat.
It was the standard greeting in AIM chatrooms too. It was still a novelty to chat with someone unknown from somewhere else in the world, so it was neat to know where they were.
Age/Sex/Location?