In an Invoice line (ibg-25) where the invoiced Item tax category code (ibt-151) is “G (Free export item, tax not charged)” the invoiced Item tax rate (ibt-152) shall be 0 (zero).
cac:InvoiceLine/cac:Item/cac:ClassifiedTaxCategory[normalize-space(cbc:ID) = 'G'][cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT'] | cac:CreditNoteLine/cac:Item/cac:ClassifiedTaxCategory[normalize-space(cbc:ID) = 'G'][cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT'](xs:decimal(cbc:Percent) = 0)