Семантическая разметка для Социальных сетей

 Open Graph Protocol

5 базовых типов материалов

https://www.optimizesmart.com/how-to-use-open-graph-protocol/
https://developers.facebook.com/docs/sharing/opengraph
https://developers.facebook.com/docs/reference/opengraph/object-type/website/
http://ogp.me/

The four required properties for every page are:

• og:title - The title of your object as it should appear within the graph, e.g., "The Rock".
• og:type - The type of your object, e.g., "video.movie". Depending on the type you specify, other properties may also be required.
• og:image - An image URL which should represent your object within the graph.
• og:url - The canonical URL of your object that will be used as its permanent ID in the graph, e.g., "http://www.imdb.com/title/tt0117500/".

Discussion and support

You can discuss the Open Graph Protocol in the Facebook group or on the developer mailing list. It is currently being consumed by Facebook (see their documentation), Google (see their documentation), and mixi. It is being published by IMDb, Microsoft, NHL, Posterous, Rotten Tomatoes, TIME, Yelp, and many many others.

Вставка OGP-разметки через PHP

Articles разметка

http://designcenter.org.ua/articles/web-verstka/meta-tegi-i-s-chem-ix-edyat-meta-property

http://sixrevisions.com/html5/download-attribute/