Turning on JAXP validation would however do nothing to validate our parser implementations match the schema. At runtime the schemas are as good as non-existent, it does not matter if the XML does or does not match the schema if the parser does not match the schema.
This proposed change firstly allows the error reporting to be centralised allowing the current error reporting code in the parsers to be removed, secondly the change in calls allows us to provide a test framework that validates the calls made by the parser do match the definition in the schema.