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.
Google+ platform websites integration using the Google+ platform tag.
Let visitors recommend your content on Google Search and share it on Google+.
Pinterest is a social networking site with a visually-pleasing virtual pinboard interface. Users collect photos and link to products they love, creating their own pinboards and following the pinboards of other people whom they find interesting. The site has experienced rapid growth in recent months.
Open graph description entity tag
Sites who has this tag are verfied by google to use WebMaster tools