AFK messages allow you to automatically display a message to users who ping you. This allows you to explain why you might not be responding or when you'll be back. AFK messages have a 100 character limit to prevent abuse and you are unable to use clickable links/user mentions in the message. Currently AFK messages are permanent and will last until you or a server admin removes it.
You are able to set your own AFK message by typing
!afk <message>. If you ever forget what you have your AFK message set to you can always type
!afk without any message and it'll show what message you currently have set. (If one is set)
You are able to remove your own AFK message by typing the