I have done a fairly thorough analysis of the bit-order issue. Bit order only matters when an element constructs a value from part of a byte, or spans bytes, with a partial byte somewhere on one end, the other, or both. The attached spreadsheet walks through all the cases. 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>