Identifies administrators for a page which will be able publish data to your wall if you like any content within this page.
Facebook's Like button is the quickest way for people to share content with their friends. A single click on the Like button will 'like' pieces of content on the web and share them on Facebook. You can also display a Share button next to the Like button to let people add a personal message and customize who they share with.
Open graph description entity tag
Sites who has this tag are verfied by google to use WebMaster tools