One of the most popular features on Facebook is tagging, which gives you the ability to identify and reference to someone in your status, photos, videos, and notes. People often leave comments on one status update to share their thoughts and feelings. Sometimes including references to friends.
Facebook Comments Tagging is another way to let people know to whom you are speaking. Facebook users can also post a comment without having to click "Post", but just press Enter on the keyboard.
When you write comments, and want to add a friend's name to something you are posting, simply add "@" symbol before your friend's name. When you type a name, a drop-down menu will appear that allows you to select the names of friends on the list.