Specification identifier MUST have the value 'urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0'.
ubl-creditnote:CreditNote | ubl-invoice:Invoicestarts-with(normalize-space(cbc:CustomizationID/text()), 'urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0')