I am one of the authors of the WebRuleLanguage, which is considered as an input to the RIF Working Group.
The following study in the representational issues which arise when combining rules and ontologies might be of interest to this working group:
Jos de Bruijn, Thomas Eiter, Axel Polleres, Hans Tompits: "On Representational Issues about Combinations of Classical Theories with Nonmonotonic Rules", DERI Technical Report 2006-05-29. To be published as an invited paper in the Proceedings of the First International Conference on Knowledge Science, Engineering and Management (KSEM'06), LNAI, Springer-Verlag.
A proposed clarification of the use of OWL knowledge bases as data: Ways of using OWL KBs as data