Message

[PEPPOL-T004-R019] DocumentTypeCode MUST be one of 'PRO' or 'REQ' or '916'.

Context
ubl:CallForTenders/cac:AdditionalDocumentReference/cbc:DocumentTypeCode
Test
matches(normalize-space(.),'^(PRO|REQ|916)$')
Usage
/ t004:CallForTenders / cac:AdditionalDocumentReference / cbc:DocumentTypeCode