Message

Tax Category E MUST be used when exemption reason code is VATEX-EU-F

Context
cac:TaxCategory[upper-case(cbc:TaxExemptionReasonCode)='VATEX-EU-F']
Test
normalize-space(cbc:ID)='E'
Usage
/ ubl:Invoice / cac:TaxTotal / cac:TaxSubtotal / cac:TaxCategory / cbc:TaxExemptionReasonCode