The message will be: Checked out.
Why you see the warning message: CHECKED OUT
The warning message "checked out" means that another user:
- did not correctly close the Article or other item that they were editing, or
- they are still editing the item you want to edit.
When an item is 'checked out' then no-one else may edit it until Global Checkin is performed.
It is a good idea from time to time to take a look and see if there are any checked out items.
And check them back in.
You can do this using the Global Checkin screen of your website's control panel.