If you are creating a reference via carrier code or ACI, the parent_reference_id value will be null.
When tracking of containers is initiated from a master bill of lading or booking number, all references created at the container level will have a parent_reference_id property set to the parent reference's reference_id. This will allow you to easily group shipments together as you receive updates for each container.
Tips for using parent references
- Once a parent reference has been generated and discovers its existing child references, it will no longer search for new child references even while still active. We will also not remove any created child references for the same reason.
- If active, the parent reference ID can be used to query the API's List Reference Updates endpoint to easily retrieve the latest update payload for each active child reference.