Open Graph Protocol Markup

og.html

<meta property="og:title" content="" /> <!-- post/page title -->
<meta property="og:type" content="" /> <!-- post/page type -->
<meta property="og:image" content="" /> <!-- post/page image -->
<meta property="og:url" content="" /> <!-- post/page url -->
<meta property="og:description" content="" /> <!-- post/page description -->
<meta property="og:site_name" content="" /> <!-- Site Name -->

The og:type property is usually going to have it's content value set to website.

You can find a list of all the possible object types here:
http://ogp.me/#types