See this Pull Request: https://github.com/OpenGridForum/DFDL/pull/57 to comment, or this to read the document: https://github.com/OpenGridForum/DFDL/blob/4b1f50220ee064f662e6fe1339f84916d... Mike Beckerle Apache Daffodil PMC | daffodil.apache.org OGF DFDL Workgroup Co-Chair | www.ogf.org/ogf/doku.php/standards/dfdl/dfdl Owl Cyber Defense | www.owlcyberdefense.com