Message

An allowance percentage MUST NOT be negative.

Context
/ubl:Invoice/cac:AllowanceCharge
Test
not(cbc:MultiplierFactorNumeric) or number(cbc:MultiplierFactorNumeric) >=0
Usage
/ ubl:Invoice / cac:InvoiceLine / cac:Price / cac:AllowanceCharge / cbc:MultiplierFactorNumeric