Message

[PEPPOL-T004-R015] listID for LocaleCode MUST be 'ISO639-1'.

Context
ubl:CallForTenders/cac:AdditionalDocumentReference/cbc:LocaleCode
Test
normalize-space(./@listID)='ISO639-1'
Usage
/ t004:CallForTenders / cac:AdditionalDocumentReference / cbc:LocaleCode / @listID