Do active references created via master bill of lading count toward my reference limit?

This article answers that references tracking the master bill of lading (or parent references) are not billable and only the child references tracking each container are billable

The creation of a parent reference based on a provided bill of lading is not billable.
To provide an example, a bill of lading that is used to track 10 containers will count as 10 active references only. The parent reference is used as a base to determine how many containers need to be tracked and each child reference will have its own unique reference ID.