(a) Except for those contracts pertaining to matters under the supervision and control of the Board of Public Affairs, the Mayor shall be the contracting officer for the City. The Board of Public Affairs shall be the contracting authority in regard to matters under its supervision and control.
(b) All contracts shall be in written form. The contracting officer or authority designated in division (a) of this section shall award and sign all contracts on behalf of the City, and such contracting officer or authority may designate any other administrative officer or employee of the City as purchasing agent, and authorize such purchasing agent to make all contracts on behalf of the City, where advertising and bidding are not required. The contracting officer or authority may adopt such rules and regulations as they deem necessary concerning the purchasing and contracting policies and procedures of the City for those matters under their respective supervision and control.