microdata

Microdata is a standard for annotating web pages with machine readable data. It is similar to microformats, but whereas microformats target specific kinds of data, such as addresses, microdata is a generic data embedding nethod. Larger parts of a page are marked up to say what type of thing they are refering to and then within each properties are defined. Microdata often uses the standard ontologies in schema.org.

<p itemscope itemtype="http://schema.org/Book">
    A new book is being published <span itemprop="title">An Introduction to
    Artificial Intelligence, second edition</span>,
    by <span itemprop="author" itemscope itemtype="http://schema.org/Person">
        <span itemprop="givenName">Alan</span>
        <span itemprop="familyName">Dix</span>
        (born <span itemprop="birthPlace">Cardiff</span>,
        <span itemprop="birthDate" datetime="1960-07-28">1960</span>)
    </span>
</p>