A risk that underwriters do not care to insure but are nonetheless assigned by the state because state law requires the insured be protected.
A risk not be generally acceptable to any insurance company but for which the law says that insurance must be acquired. Personal auto liability is one such necessary coverage. Insurance companies doing personal auto business in a state can be required to accept assignment of a portion of the state's unacceptable drivers as insureds.
special plans which are created to provide auto and workers compensation insurance for individuals unable to obtain same in the voluntary market.