As used in this section, "professional employee" has the same meaning as in section 5126.20 of the Revised Code and "registered service employee" means a service employee, as defined in section 5126.20 of the Revised Code, who is registered under section 5126.25 of the Revised Code.
County boards of developmental disabilities may hire professional employees and registered service employees in the classified service on the basis of the candidates' qualifications rather than on the basis of the results of a civil service examination, as described in division (D) of section 124.23 of the Revised Code.