Google Publisher Tag (GPT) is an ad tagging library with which you can dynamically build ad requests. GPT takes key details from you such as ad unit name, ad size, and custom targeting, builds the request, and displays the ad on web pages or mobile apps.
Identifies administrators for a page which will be able publish data to your wall if you like any content within this page.
This site uses the viewport meta tag which means the content may be optimized for mobile content.
This meta tag tells Google not to show the sitelinks search box.
Sites who has this tag are verfied by google to use WebMaster tools
Open graph description entity tag