UBL-SR-52
Document reference shall occur maximum once
What the rule checks
As the rule set's publisher wrote it. The rule runs on every element the context matches, and fails where the test is false; the validator reports the line of that element.
cac:InvoiceLine | cac:CreditNoteLinecount(cac:DocumentReference) <= 1Checked with EN 16931 Invoice (UBL), EN 16931 Credit Note (UBL), Croatia eRačun Invoice (UBL), Croatia eRačun Credit Note (UBL)