FX-SCH-A-000137
A VAT Breakdown (BG-23) with VAT Category code (BT-118) "Reverse charge" shall have a VAT exemption reason code (BT-121), meaning "Reverse charge" or the VAT exemption reason text (BT-120) "Reverse charge" (or the equivalent standard text in another language).
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.
[BR-AE-10] A VAT Breakdown (BG-23) with VAT Category code (BT-118) "Reverse charge" shall have a VAT exemption reason code (BT-121), meaning "Reverse charge" or the VAT exemption reason text (BT-120) "Reverse charge" (or the equivalent standard text in another language).
//rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeSettlement/ram:ApplicableTradeTax/ram:CategoryCode[. = 'AE']
(../ram:ExemptionReason) or (../ram:ExemptionReasonCode)
Checked with Factur-X / ZUGFeRD BASIC