Rules are logical limitations or cases placed upon a set of data or transfer of data.
"Rules in (and for) the Web have become a mainstream topic since inference rules were marked up for E-Commerce and were identified as a Design Issue of the Semantic Web, and since transformation rules were put to practice for document generation from a central XML repository (as used here). Moreover, rules have continued to play an important role in AI shells for knowledge-based systems and in Intelligent Agents, today both needing a Web interchange format, and such XML/RDF-standardized rules are now also usable for the declarative specification of Web Services."
- RuleML Home: http://www.ruleml.org/
The mission of the Rule Interchange Format (RIF) Working Group is to produce W3C Recommendations for rules interchange
- RIF Core: http://www.w3.org/TR/rif-core/
- RIF Working Group: http://www.w3.org/2005/rules/wiki/RIF_Working_Group