We don't stipulate that textBooleanTrueRep nor textBooleanFalseRep cannot be empty string. We do stipulate that entity ES is not allowed. So I expect these properties cannot be "" meaning the same thing that "%ES;" would mean. Since we disallow the latter, we should disallow just "". Similarly, for textStandardGroupingSeparator, textStandardExponentRep, textStandardNaNRep, and textStandardInfinityRep we specify that the string literal value behaves as specified in textStandardDecimalSeparator, but we don't specify that these cannot be empty string (which is specified in textStandardDecimalSeparator, but not in the "Text Number Character Restrictions" part of that property description that is referenced from these other properties.) ES and WSP* are not allowed, so almost certainly empty string should not be allowed. 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>