warningEN 16931syntax binding ruleUBL
A UBL invoice should not include the InvoiceLine DocumentReference LanguageID
The element 'InvoiceLine DocumentReference LanguageID' is present, but it carries no meaning in the EN 16931 semantic model, so a receiver is free to ignore or reject it.
Remove 'InvoiceLine DocumentReference LanguageID' from the document. Nothing in EN 16931 maps to it - it is almost always left over from a generic UBL template. Reported as a warning.
UBL — context /ubl:Invoice | /cn:CreditNote
not((cac:InvoiceLine|cac:CreditNoteLine)/cac:DocumentReference/cbc:LanguageID)