While Jack owned the office building, he also put Jim's name on the fire insurance policy so that practical matters after such a possible event could be handled by them both, making Jim the additional insured.
You may want to make sure that a shipment is additional insured if it is very valuable and you don't want the risk.
After the accident, Karen knew she'd be in trouble with her insurance company if they found out the driver (her boyfriend) wasn't one of the additional insured on the vehicle.