Hurray! I thought this day would never come… Google has recently announced its support for RDFa along with microformats. This is great news, they now join Yahoo in supporting the W3C RDFa standard for embedding data along with the content. Think of RDFa as more flexible microformats.
Google is calling this “Rich Snippets” . If Google comes across embedded data in your pages it will give your returned result a much richer looking appearance. Initially Google will support only two types of objects in their Rich Snippets: People and Reviews. I am sure that googlebot will index any embedded metadata, but for now will only expose marked up People and Reviews.
Another exciting use of this is with Google Custom Search engines. Using their APIs you will have much more control over the data within your own site. You will also be able to use any custom vocabularies, a nice addition over the Google search engine behaviour.
Google is quick to point out that this will not necessarily affect your search results, but leaves it to their secret recipes to decide what to do.
Here is a short blurb from Google on what this additional markup aims to achieve:
How microformats and RDFa work
Imagine that you have a review of a restaurant on your page. In your HTML, you show the name of the restaurant, the address and phone number, the number of users who have provided reviews, and the average rating. People can read and understand this information, but to a computer it is nothing but strings of unstructured text. With microformats or RDFa, you can label each piece of text to make it clear that it represents a certain type of data: for example, a restaurant name, an address, or a rating. This is done by providing additional HTML tags that computers understand. These don’t affect the appearance of your pages, but Google and any other services that look at the HTML can use the tags to better understand your information, and display it in useful ways—for example, in search results.
You can use either whichever standard you prefer—microformats or RDFa— and you don’t need to understand one in order to use the other.
Here are the current vocabularies that Google understands:
For a long time Yahoo has supported microformats and RDFa in content that it indexes from the Web. They have been big pushers in this area, using their BOSS API along with Searchmonkey, a lot of interesting things have been possible.
An RDFa tutorial “RDFa for HTML Authors” is being created on the W3C site as we speak. It is not yet totally finished, but gives a good overview along with lots of good examples.
Now that Google is supporting structured data it is high time to learn how to use this stuff. So go have a read and start marking up your data. They have a lot of good examples (please note, that some of their markup is not currently valid, so keep your eyes open for updates). Even Google can get some things wrong ;)