The RVW specification is a module extension to the RSS 2.0 syndication format. RVW is intended to allow machine-readable reviews to be integrated into an RSS feed, thus allowing reviews to be automatically compiled from distributed sources.  In other words, you can write book, restaurant, movie, product, etc. reviews inside your own website, while allowing them to be used by Amazon or other review aggregators.

Aww, yeah. Bring on the microcontent. Yay, hooray! This is an XML namespace-based extension to RSS 2.0, and for even more flavor, it uses the work of other pre-existing specs, such as ENT, FOAF, and Dublin Core. This wouldn't be hard at all to slip into an RSS 1.0 feed and an RDF database as well.