Open graph description entity tag
A WebSite is a set of related web pages and other items typically served from a single web domain and accessible via URLs.
A scheme.org entity that represents a person (alive, dead, undead, or fictional).
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.