A family of standard web feed formats used to publish frequently updated information like blog entries, news headlines, audio and video.
Allows a website to define how a page is rendered in Internet Explorer 8, allowing a website to decide to use IE7 style rendering over IE8 rendering.
Open graph description entity tag
The Open Graph protocol enables any web page to become a rich object in a social graph, a open protocol supported by Facebook
A WebSite is a set of related web pages and other items typically served from a single web domain and accessible via URLs.
Any offered product or service. For example: a pair of shoes; a concert ticket; the rental of a car; a haircut; or an episode of a TV show streamed online.
Sites who has this tag are verfied by google to use WebMaster tools
The http-equiv attribute provides an HTTP header for the information/value of the content attribute. The http-equiv attribute can be used to simulate an HTTP response header.