Open graph description entity tag
The average rating based on multiple ratings or reviews.
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
A canonical link element is an HTML element that helps webmasters prevent duplicate content issues by specifying the "canonical", or "preferred".
By adding rel="home" to a hyperlink, a page indicates that the destination of that hyperlink is the homepage of the site in which the current page appears.