sitting with Don Smith and Peter Provost, Peter discussed schema tools support and the "russian doll" model. This refers to having nested complex types in the generated schema (anonymous types) versus the "venetian blind" model, where you specify global complex and simple types. Considering the guidance from Don, Tim, and Gudge's talk in 2003's PDC XML precon session to favor the venetian blind model, I thought this was a very appropriate analogy. Use global types, and specify the root element of a type that includes or extends global types.