For those who like (to argue about) semantics, HTML5 is fantastic. Old presentational elements now have new semantic meanings, there’s a slew of new semantic elements for us to argue about, and we've even in<cite>d a riot or two. But that's not all! Also in HTML5 is microdata, a new lightweight semantic meta-syntax. Using attributes, we can define nestable groups of name-value pairs of data, calle