Specification identifier MUST begin with the value 'urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0' and follow the format rules for the identifier.
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') and not(contains(normalize-space(cbc:CustomizationID/text()), '::'))