RDFa

And once more Bob DuCharme has written an exquisite article, published by IBM developerWorks, called Put XHTML 2 to work now. To sum up the main idea of the article:

Many publishers that store content in XML have always known that using an existing, standard schema (by which I mean a W3C Schema, a RELAX NG schema, or a DTD) was better than creating their own from scratch. They looked at DocBook and found it too complex; they looked at HTML or XHTML 1 and found it too simple. For many of them, XHTML 2 will hit a sweet spot between the richness of DocBook and the simplicity of XHTML 1 that makes it a perfectly good format for storing content, whether that content has to be converted to other formats for delivery in various media or not.

What I liked best? The section Easier addition of metadata, where he writes about RDFa