How to setup a custom login screen message on macOS
Updated 2021-12-01 · Published 2016-12-11
You can display a custom message to be displayed on the login screen of your macOS system. This is different from setting a policy banner that a user must accept before they are allowed to continue. Run the following command from the terminal in order to enable or disable a custom message.
Enable a custom message
sudo defaults write /Library/Preferences/com.apple.loginwindow LoginwindowText "powered by saucepan.org"
Disable a custom message
sudo defaults delete /Library/Preferences/com.apple.loginwindow LoginwindowText