This function says it can be called on non-array elements. However, it does not say what the result is. If called when "." is not itself an array element there are only two possible behaviors consistent with the fact that it is explicitly allowed on non-array elements. The result has to be either (a) 1 (b) the occursIndex of the nearest enclosing array parent, or 1 if there is no enclosing array parent. I claim (a) is fairly pointless. You will just end up having to create newVariableInstances to carry the array current index downward into expressions. I cannot think of a use case where one would want to call occursIndex() polymorphically, i.e., where you want a number in the case of an array, but 1 otherwise. So (b) is the preferable behavior. 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>