In his 4 years at DecisionSoft, Paul Warren has gained extensiveexperience of real world applications of XML validation. As part ofDecisionSoft's involvement with many UK government e-Filing projects,Paul has played a key role in translating business data constraints intoXML validation components, and has found that from a businessperspective, the split between what can and cannot be encompassed in XMLSchema validation appears arbitrary. As a result, these validationcomponents are made up of standard XML Schema validation augmented witha proprietary rules engine. DecisionSoft are keen to develop astandardised mechanism for beyond-schema validation, and feel thatrecent developments such as XPath2, XQuery, and the general move towardsmaking schema validation information available in applications, thefoundations for an extremely powerful validation system are already inplace.