This site uses the viewport meta tag which means the content may be optimized for mobile content.
Polyfill is a service which accepts a request for a set of browser features and returns only the polyfills that are needed by the requesting browser.
UTF-8 (8-bit UCS/Unicode Transformation Format) is a variable-length character encoding for Unicode. It is the preferred encoding for web pages.
Sites who has this tag are verfied by google to use WebMaster tools
This page contains a meta robots tag which tells search engines and robots to index or not index the page.
The Open Graph protocol enables any web page to become a rich object in a social graph, a open protocol supported by Facebook