BR-CIUS-PT-16
A VATBReakdown (BG-23) with VAT Category code (BT-118) "Exempt from VAT" the VAT category rate (BT-119) shall be 0 (zero).
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.
cac:TaxTotal/cac:TaxSubtotal/cac:TaxCategory[normalize-space(cbc:ID) = 'E' or normalize-space(cbc:ID) = 'ISE']
(cbc:Percent = 0)
Checked with Portugal CIUS-PT Invoice (UBL), Portugal CIUS-PT Credit Note (UBL)