Every employer of workers with disabilities under special minimum wage certificates authorized by the Fair Labor Standards Act, the McNamara-O'Hara Service Contract Act, and/or the Walsh-Healey Public Contracts Act shall display a poster prescribed by the Wage and Hour Division explaining the conditions under which special minimum wages may be paid. The poster shall be posted in a conspicuous place on the employer's premises where employees and the parents or guardians of workers with disabilities can readily see it.