An identifier of a referenced Sales order, issued by the Seller. In cases where sales order reference is provided, but there's no purchase order reference, then set cac:OrderReference/cbc:ID to value "NA" as this element is mandatory in UBL.

Cardinality
0..1
Namespace
cbc urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2
Data type
Document Reference
Example value
112233
Business terms
BT-14