With reference to the rules of the Public Service Commission (PSC) dealing with meeting procedures, (a) how does the PSC deal with the leadership of meetings in the absence of the Chairperson and/or Deputy Chairperson, (b) when were the specified rules adopted, (c) when were the relevant sections of the rules that deal with vacancies in the leadership of the PSC last revised and (d) what is the exact wording of the sections that deal with the absence of the Chairperson and/or Deputy Chairperson during PSC meetings.