Usage: MESSAGES RESET <numeric>|ALL

Resets a specific message back to its default value. To get a list of changed messages simply type: /as messages. The all command will reset all messages back to their original values.

/as messages reset 481
/as messages reset all

If you have changed a message and realize that you dislike your changes this is an easy way to undo them. This is particularly useful if you want to change all of your messages.