An application can relinquish ownership of a call by invoking lineSetCallPrivilege to change to a monitor application, or simply by using lineDeallocateCall to indicate that it has no further interest in the call. If the application is the sole owner of the call and cannot hand off ownership to another application, TAPI will not permit it to change to being a monitor or to deallocate its call handle—in this situation, the application has no choice but to drop the call.