I finally got around to enhancing the mil-std-2045 schema using the ideas that came out of review of the original work. It is vastly improved in terms of complexity of the schema, and other schemas that have to generate this sort of thing are greatly simplified by the techniques illustrated here which avoid the need to generate any top-level group definitions. I did have to put in the workaround of using "WSP*" in a terminator instead of "ES" because Daffodil doesn't support ES in terminators yet (there's a bug). I also left out the defaults, which are needed for unparsing, due to a bug in Daffodil. https://github.com/DFDLSchemas/mil-std-2045 Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | www.tresys.com Please note: Contributions to the DFDL Workgroup's email discussions are subject to the OGF Intellectual Property Policy http://www.ogf.org/About/abt_policies.php