Those persons who become miscellaneous officers and employees after November 1, 1976, shall be members of the Retirement System subject to the provisions of Sections 8.584 and 8.584-1 through 8.584-12, in addition to the provisions contained in Sections 3.670, 3.672, 8.500, 8.510, 8.520 and 8.526 of this Charter notwithstanding the provisions of any other section of the Charter; provided that persons who become members under the Public Employees' Retirement System of the State of California pursuant to Section 8.506 of this Charter of members of State Teachers' Retirement System of the State of California pursuant to Section 8.506-1 of this Charter shall not be members of the San Francisco City and County Employees' Retirement System and provided, further, that the Retirement System shall be applied to persons employed on a part-time, temporary or substitute bases only as the Board of Supervisors shall determine by ordinance enacted by three-fourths vote of all members of the board. Miscellaneous officers and employees who are members of the Retirement System under Sections 8.507 or 8.509 of the Charter prior to November 2, 1976 shall continue to be members of the system under Sections 8.507 or 8.509, as the case may be, and shall not be subject to any of the provisions of this section or Sections 8.584-1 through 8.584-12.