Message

[PEPPOL-COMMON-R056-1]-Dutch VAT numbers (9944) MUST be stated in the correct format (NL123456789B12).

Context
cbc:EndpointID[@schemeID = '9944'] | cac:PartyIdentification/cbc:ID[@schemeID = '9944'] | cbc:CompanyID[@schemeID = '9944']
Test
matches(normalize-space(), '^NL[0-9]{9}B[0-9]{2}$')