EHF ESPD 1.2 | Rules | EHF-ESPD-RES-B15901

Message: Element 'cac:ExternalReference' MUST be provided.
Context: ccv:Requirement/ccv:Response/cev-cac:Evidence/cev-cac:EvidenceDocumentReference/cac:Attachment
Test: cac:ExternalReference
Usage: / espd:ESPDResponse / ccv:Criterion / ccv:RequirementGroup / ccv:Requirement / ccv:Response / cev-cac:Evidence / cev-cac:EvidenceDocumentReference / cac:Attachment