In an Invoice line (BG-25) where the Invoiced item VAT category code (BT-151) is "IGIC" the invoiced item VAT rate (BT-152) shall be 0 (zero) or greater than zero.
cac:InvoiceLine/cac:Item/cac:ClassifiedTaxCategory[normalize-space(cbc:ID) = 'L'][cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT']| cac:CreditNoteLine/cac:Item/cac:ClassifiedTaxCategory[normalize-space(cbc:ID) = 'L'][cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT'](cbc:Percent) >= 0