fatalEN 16931syntax binding ruleUBL
Document level allowance reason shall occur maximum once
'Document level allowance reason' appears more than once, and this profile allows it at most once.
Keep the single correct 'Document level allowance reason' and delete the rest. Repeating an element that the semantic model treats as singular is usually a serialiser writing every value it has instead of choosing one.
UBL — context cac:AllowanceCharge[cbc:ChargeIndicator = false()]
(count(cbc:AllowanceChargeReason) <= 1)
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.