(a) All officers elected by the people.

(b) The director and the assistant director of each department of the city government, the civil service commissioners, the purchasing agent, the city architect, and the members of the commission on city planning, and the art jury.

(c) The city solicitor and all assistant city solicitors.

(d) Persons employed by contract to perform a special service for such city, where such contract is certified by the civil service commission to be for employment which cannot be performed by persons in the classified service.

(e) Persons who in times of public emergency may be appointed as special policemen or firemen for service not to exceed one month in duration.

(f) Persons temporarily appointed or designated to make or conduct a special inquiry, investigation, or examination, where such appointment or designation is certified by the civil service commission to be for employment which should not be performed by persons in the classified service.

The classified service of such city shall comprise all civil offices, positions, and employments which are not specifically included in the unclassified service.