Lets first start with Away,
Away status tells that your brb/afk. Buuuut! You are still online, just that your User Icon has a different style icon. You can set Away option through your Edit Name/Picture/Homepage etc.
Whenever you put your status as away, you can have an auto-respond message whenever someone private chats you, it'll be something like this:
Darren: Chris you there?
Auto Respond Message from Chris: AFK, going to restart server.
Thats just the example
When too many private chats, they will close, but appear when you go to Away Pc's
Log In to Xat Registered Users --> Check Away messages!