In the world of property-casualty insurance, businesses and their advisers often deal with certificates of insurance. They are commonplace instruments that are accepted in the marketplace as reasonable assurance that certain objects or activities are covered by insurance. For example, when valuable equipment is stored in a warehouse until a construction project is ready to receive and install it, cautious owners often insist on seeing insurance certificates before paying for the merchandise in order to be assured that the property is protected against casualty losses. CONNOLLY When a contractor employs a subcontractor to perform part of the work of a