The Open Graph protocol enables any web page to become a rich object in a social graph, a open protocol supported by Facebook
This page contains a meta robots tag which tells search engines and robots to index or not index the page.
Chrome for Android, since version 39 supports the "theme-color" meta tag to allow websites control the background color of the tab's UI header.
When running in a browser on a mobile phone, "format-detection" meta tag determines whether or not telephone numbers in the HTML content will appear as hypertext links. The user can click a link with a telephone number to initiate a phone call to that phone number.
Indicates that the site provides an interface specifically for searching the document and its related resources.