In some situations we parse and get a successful zero-length parse for a string or hexBinary. But because the occurrence is optional, we do NOT add an element to the infoset. In that case, what happens to side-effects that occurred during the successful parse. There are two possible kinds of side-effects. Variables can be set, and a discriminator can be set to true. It seems to me that if a discriminator is set, then that *must* be preserved, and in that case it would seem the variable settings should be retained as well. Comments? 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>