Yandex.Maps API. Use Yandex maps for your web site or application. Create custom maps, directions, and geoinformational services.
Open graph description entity tag
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.
A canonical link element is an HTML element that helps webmasters prevent duplicate content issues by specifying the "canonical", or "preferred".