warningEN 16931syntax binding ruleUBL
A UBL invoice should not include a Buyer Item Identification schemeID
The buyer's item identification carries a schemeID.
Remove schemeID from BuyersItemIdentification/cbc:ID — it is the buyer's own article number and belongs to no registry.
UBL — context /ubl:Invoice | /cn:CreditNote
not(//cac:BuyersItemIdentification/cbc:ID/@schemeID)
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.