All materials that are supplied by the department of job and family services to type A family day-care home providers, type B family day-care home providers, in-home aides, persons seeking to be type A family day-care home providers, type B family day-care home providers, or in-home aides, and caretaker parents shall be written at no higher than the sixth grade reading level. The department may employ a readability expert to verify its compliance with this section.