Well said Johnson.
Xteria:
What this trick does is that users who have you on their lists, will see your name underlined in the buddy list, it doesn’t work in chat.
This works because pressing ctrl+enter in some windows controls creates a new line. So what happens is your status appears on a new line, because you started it off with a new line, and hence the ¯ symbol appears as though its underlining your name.