Google+ platform websites integration using the Google+ platform tag.
Let visitors recommend your content on Google Search and share it on Google+.
This site uses the viewport meta tag which means the content may be optimized for mobile content.
Open graph description entity tag
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".