The ordinance may provide that:
(a) The amount of the retirement, compensation, or pension may be predicated, in part, upon services rendered the city by an officer or employee prior to the establishment of the system.
(b) The contribution of officers and employees included in the system may be collected by deducting the amounts of such contributions from the salary or wages due the officers and employees.
(Added by Stats. 1949, Ch. 79.)