How to post a message on your Mac screen lock

Add a message on the lock screen in two ways: through the settings or by using a terminal command. Here's how it's done.

method one

1. Open the "Settings» → «The protection and security."
2. Click the lock icon and enter an administrator password.
   
3. In the "Basic" Check the box "Show a message when the screen is locked."
4. Click "Set lock message ...".
   
5. Enter the desired text and confirm with "OK".
   
6. Use a combination Control + Command + Q, to block screen and check how the message.

method two

1. Open the "Terminal" from the folder "Programs» → «Utility" or via Spotlight.
2. Copy the following command, replacing the text on your: sudo defaults write /Library/Preferences/com.apple.loginwindow LoginwindowText messagetext
3. Insert it in the "Terminal" and confirm the administrator password.
4. Press Control + Command + Q, to lock the screen and check the text on it.

To delete a message through the terminal, use the same command, but leave the text blank. Like this: sudo defaults delete /Library/Preferences/com.apple.loginwindow LoginwindowText