Facebook has created a meta tag protocol to be used when people “like” a particular page. This is called the “Open Graph Protocol”.
The Open Graph Protocol lets you integrate your Web pages into the Facebook social graph. It is designed for Web pages that represent real-world things — for example, movies, sports teams, celebrities, and restaurants.
By placing Open Graph tags on your Web page, you can make your page equivalent to a Facebook Page. This means that when a user clicks a Like button on your page, a connection is made between your page and the user. Your page will appear in the “Likes and Interests” section of the user’s profile, and you have the ability to publish updates to the user. Your page will show up in the same places that Facebook pages show up around the site (e.g. search), and you can target ads to people who like your content.
The Open Graph Protocol lets you define how your page will be represented on Facebook.
See the Facebook page on their Open Graph Protocol.
We have also built a generator that lets you generate facebook open graph meta tags.