Is this just an oversight? I find it very tedious to model if I can't put the asserts on the simpleTypes so that I don't have to repeat them over and over in the model. The composition rule here is simple. If an element has asserts, and its simple type has asserts, both are executed, with the element's asserts run after the simpleType's asserts. ...mike -- Mike Beckerle | OGF DFDL WG Co-Chair Tel: 781-330-0412