Confirmation Messages section displays a list of messages that were disabled by the user and can be reactivated. For example, when you run a rule and you don't save changes before running, you can check Don't show this message again on Rule was successfully updated message. After that, this message will be displayed in the Disabled Messages list:
To reactivate the message, select it in the list and click Enable.
Confirmation Messages is introduced as a separate item in Administrator Console tree.