FX-SCH-A-000092
In a Document level allowance (BG-20) where the Document level allowance VAT category code (BT-95) is "IPSI" the Document level allowance VAT rate (BT-96) shall be 0 (zero) or greater than 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.
[BR-AG-06] In a Document level allowance (BG-20) where the Document level allowance VAT category code (BT-95) is "IPSI" the Document level allowance VAT rate (BT-96) shall be 0 (zero) or greater than zero.
//ram:SpecifiedTradeAllowanceCharge[ram:ChargeIndicator/udt:Indicator='false']/ram:CategoryTradeTax[ram:CategoryCode = 'M']
ram:RateApplicablePercent >= 0
Checked with Factur-X / ZUGFeRD BASIC