Message

Value MUST be part of code list 'Country codes (ISO 3166-1:Alpha2)'.

Context
/ubl:DespatchAdvice/cac:Shipment/cac:Delivery/cac:Despatch/cac:DespatchAddress/cac:Country/cbc:IdentificationCode
Test
(some $code in $clISO3166 satisfies $code = normalize-space(text()))
Code lists
Country codes (ISO 3166-1:Alpha2)
Usage
/ ubl:DespatchAdvice / cac:Shipment / cac:Delivery / cac:Despatch / cac:DespatchAddress / cac:Country / cbc:IdentificationCode