ibr-122-ae
When Invoice type code (IBT-003) is 'Out of scope of VAT' or 'Credit note related to goods or services', then the Document level allowance VAT category code (IBT-095), Document level charge VAT category code (IBT-102), Invoiced item VAT category code (IBT-151) MUST be either 'Exempt from VAT' and/or 'Not subject to VAT' and/or 'Zero rated'.
What the rule checks
As the rule set's publisher wrote it. The rule runs on every element the context matches, and fails where the test is false; the validator reports the line of that element.
/ubl:Invoice | /cn:CreditNote
not((cbc:InvoiceTypeCode | cbc:CreditNoteTypeCode) = "81" or (cbc:InvoiceTypeCode | cbc:CreditNoteTypeCode) = "480") or (every $cat in (//cac:TaxCategory/cbc:ID | //cac:ClassifiedTaxCategory/cbc:ID) satisfies normalize-space($cat) = ("E","O","Z"))
Checked with PINT UAE Invoice, PINT UAE Credit Note