Basically it is that each time a user "x" connect to osu, get some kind of message to alert you to connect. It would be a convenient if you are afk and wait for a single user to log in (It is annoying to be aware when are doing something else and you have to be looking osu window to see if anyone was connected or not) You could put your friends nicknames such as when you put the "Chat highlight words" or "Chat ignore list".