Suppose field 1 is 3 bits long. Suppose field 2 is a string in utf-8. dfdl:emptyValueDelimiterPolicy='none' If field2 has any contents, then those characters must begin on a byte boundary, so before the first character we will skip 5 bits. What if field2 is of length 0 ? Do we skip 5 bits anyway or not? Note that if dfdl:emptyValueDelimiterPolicy is "both", and an initator or terminator is defined, then even if length is 0 we definitely will unparse a character at least so the 5 bits of alignment are needed in that case. But if there is no framing, and no content, do we align to the text mandatory alignment or not? Now, I believe the answer to this should be "yes" we skip the 5 bits anyway. Because if field 2 is lengthKind='pattern', then when parsing, we have to scan for a match to the pattern, and so we have to know where to start the scan, which has to be at a byte boundary. So even if there is no match, so the length at parse time is zero, we still had to skip 5 bits before we could start scanning. So to be consistent with this, I believe unparsing must also output the 5 bits regardless of whether the string is length 0 or not. So there's what should it do, but also if all the constructs for this work in IBM DFDL, I'm curious what it actually does. Thanks 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>