twitter card meta tags
<meta name="twitter:card" content="summary" /> <meta name="twitter:site" content="@nytimesbits" /> <meta name="twitter:creator" content="@nickbilton" /> <meta property="og:url" content="http://bits.blogs.nytimes.com/2011/12/08/a-twitter-for-my-sister/" /> <meta property="og:title" content="A Twitter for My Sister" /> <!-- Additional Meta's --> <meta property="og:description" content="In the early days, Twitter grew so quickly that it was almost impossible to add new features because engineers spent their time trying to keep the rocket ship from stalling." /> <meta property="og:image" content="http://graphics8.nytimes.com/images/2011/12/08/technology/bits-newtwitter/bits-newtwitter-tmagArticle.jpg" />
twitter card tags
<meta name="twitter:card" content="summary" /> <meta name="twitter:site" content="@flickr" /> <meta name="twitter:title" content="Small Island Developing States Photo Submission" /> <meta name="twitter:description" content="View the album on Flickr." /> <meta name="twitter:image" content="https://farm6.staticflickr.com/5510/14338202952_93595258ff_z.jpg" />
Source: developer.twitter.com