http://www.ibm.com/developerworks/wikis/display/db2xml/Rules
Representing rules in XML is usually to make rule exchange between systems and applications simpler. This demonstration illusrates the benefits of storing rules in XML. It shows the querying of stored RIF-BLD rules through XQuery. It also demonstrates the ease with which rules stored as XML can be exposed as feeds, and as Web Services and RESTful services for applications and people to process.