warningEN 16931syntax binding ruleUBL
Unit code list identifier attribute should not be present
'Unit code list identifier attribute' is present, but this profile does not allow it — nothing in the EN 16931 semantic model maps to it.
Remove 'Unit code list identifier attribute'. It is almost always left over from a generic template or a library that emits every field of the underlying schema. Reported as a warning.
UBL — context /ubl:Invoice | /cn:CreditNote
not(//@unitCodeListIdentifier)
Nothing is stored, and the whole invoice is checked, not just this rule. A PDF only works if it is Factur-X / ZUGFeRD — a PDF with the invoice XML inside it.