Final answer:
A shipper returning an unsigned broker-shipper contract with suggested changes is making a counteroffer, presenting new terms for the contract.
Step-by-step explanation:
When a shipper sends back an unsigned broker-shipper contract with suggested changes, lawyers refer to this action as a counteroffer. This means that the shipper does not agree with the initial terms presented and is proposing new terms for the agreement. By law, a counteroffer voids the original offer and puts forth a new set of terms that the original party must accept, reject, or negotiate further. It's an essential part of contract negotiations and an opportunity for both parties to reach an agreement that is satisfactory to their interests.