go to post Jakub Hemala · Nov 8, 2023 Okay, with a bit of fiddling, that did the trick. I have attempted to set PrefixMappings in my previous solutions but it appears I did it wrong then. Output: HSROUTER>Set tPnRXML.PrefixMappings="ns urn:oasis:names:tc:ebxml-regrep:xsd:rs:3.0" HSROUTER>w tPnRXML.EvaluateExpression("/XMLMessage/ContentStream/ns:RegistryResponse/ns:RegistryErrorList/ns:RegistryError","@errorCode",.tPnRResult) 1 HSROUTER>w tPnRResult.Size 0 HSROUTER>w tPnRXML.EvaluateExpression("/ContentStream/ns:RegistryResponse/ns:RegistryErrorList/ns:RegistryError","@errorCode",.tPnRResult) 1 HSROUTER>w tPnRResult.Size 0 HSROUTER>w tPnRXML.EvaluateExpression("/ns:RegistryResponse/ns:RegistryErrorList/ns:RegistryError","@errorCode",.tPnRResult) 1 HSROUTER>w tPnRResult.Size 1 HSROUTER>w tPnRResult.GetAt(1).Value XDSRegistryDeprecatedDocumentError Thank you very much.