The order can be referred to at header level or here. Doing it here at line level it is possible to refer to multiple order in one document.

Namespace
cac urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2
Child elements
Card Name Description
0..1 cbc:ID

Order number
The order number referred to.

Example value: AEG012345

0..1 cbc:SalesOrderID

Sales order number
Reference to the sellers order number.

Example value: 5678985

Rules
Identifier/Error message Flag
PEPPOL-T128-B18401
Document MUST NOT contain elements not part of the data model.
fatal