On 7th Feb Facebook posted a message at the top of Pages on the social network to notify administrators that their the names will soon start to show up next to their posts and comments.Starting on February 20th Feb.
Administrators often wonder, “If multiple people help manage my page, how can I see who posted something?” With this new feature, page administrators will be able to see just that. “Below the name of your page and next to posted by” and “Below the comment next to commented on by,” the name of a person will be displayed. And remember that only people who manage your Page will be able to see this information.
The Learn More link above takes you to a Help Centre page titled If multiple people help manage my Page, how can I see who posted something?