For purposes of coverage under Part 2 (commencing with Section 2601), “employment” shall not include:
(a) Services performed for any public entity, nonprofit or for profit entity, organization, or business by an inmate of a state prison under the jurisdiction of the Department of Corrections, by an individual who is otherwise in the custody of the Department of Corrections, or by an individual who is otherwise incarcerated in any of the institutions set forth in Section 2680.
(b) Services performed for any public entity, nonprofit or for profit entity, organization, or business by a ward in the custody of the Department of the Youth Authority.