
Jun 06, '12 07:30:00AM • Contributed by: Anonymous
Go to the Security & Privacy preference pane of System Preferences. Under the General tab, check the second box, "Show a message when the screen is locked," and then edit the message using the "Set Lock Message..." button.
This message displays near the bottom of the Login window or the lock screen. You can make multiple paragraphs by pressing Option-Return to go to a new line.
[kirkmc adds: This was indeed covered several times in the past, and required futzing around with .plist files. There were hints in 2002, 2005 and 2011. This method is much simpler, and deserves a mention.]