Microformats
Emily Lewis beschreibt für scriptjunkie{} Microformats, konkret ein Teil 1 XFN, hCard in Teil 2, hCalendar und im letzten Teil die Kombination von Microformaten.
One of my favorite things about microformats is they can be combined to further increase the semantic richness of your content. In fact, several microformats require or recommend the inclusion of other microformats. For example, author information in both hReview and hRecipe (two more microformats indexed for Rich Snippets) should be marked up with hCard.