Open graph description entity tag
An offer to transfer some rights to an item or to provide a service—for example, an offer to sell tickets to an event, to rent the DVD of a movie, to stream a TV show over the internet, to repair a motorcycle, or to loan a book.
A review of an item - for example, of a restaurant, movie, or store.
A scheme.org entity that represents an organization such as a school, NGO, corporation, club, etc.
Sites who has this tag are verfied by google to use WebMaster tools