The login window appears when you're logged out of your macOS user account. Depending on your Security & Privacy preferences, it may also appear when you wake your Mac after sleep or screen saver begins. In the example below, ”Welcome to my Mac” is a custom lock message.
How to set a lock message
- Choose System Preferences from the Apple menu (), then click Security & Privacy.
- Click the lock and enter your administrator name and password.
- In the General tab, select ”Show a message when the screen is locked,” then click Set Lock Message.
- Enter your message in the text field, then click OK.
- If your IT department configured a lock message from the command line or by using managed preferences with Workgroup Manager or Profile Manager, your lock message might not appear.
- You can also set a policy banner that appears at login, and a screen saver message that appears when your Mac is left idle.