I posted this to our documents. http://redmine.ogf.org/dmsf_files/13300 This version is quite different. This version proposes that there are actually two different variations on the least-significant-bit first format. One is where the bits are actually reversed (logical 0xE2 becomes 0x47 when unparsed to a file) The other is where the bits are simply interpreted as LSB first, but the bytes are stored 'normally'. (0xE2 is in the file, but the 'first' 3 bits of it are 010, not 111.) Turns out it is this latter form that MIL-STD-2045 and related standards need, and that the Daffodil code implements today. I hope this version clarifies some things. You'll see there is a need to come up with useful names for these concepts when you read the document. ...mikeb 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>