Despatch advice line reference must occur maximum once

Despatch advice line reference (ibt-184) must occur maximum once.

Fails

<cac:DespatchLineReference>
  <cac:DocumentReference>…</cac:DocumentReference>
  <cac:DocumentReference>…</cac:DocumentReference>
</cac:DespatchLineReference>

Fix

Keep a single cac:DocumentReference here and delete the duplicates. If both values matter, one of them belongs in a different field.

Schematron

Context

cac:InvoiceLine/cac:DespatchLineReference | cac:CreditNoteLine/cac:DespatchLineReference

Test

(count(cac:DocumentReference) <= 1)

Official text: Despatch advice line reference (ibt-184) MUST occur maximum once.

Official · PINT shared rules. Severity: error. Runs on UBL XML.

Check an invoice