Message

When VAT category code is "Standard rated" (S) the VAT rate SHALL be greater than zero.

Context
cac:TaxCategory | cac:ClassifiedTaxCategory
Test
not(normalize-space(cbc:ID)='S') or (cbc:Percent) > 0
Usage
/ ubl:OrderChange / cac:AllowanceCharge / cac:TaxCategory / cbc:Percent
/ ubl:OrderChange / cac:OrderLine / cac:LineItem / cac:Item / cac:ClassifiedTaxCategory / cbc:Percent