The plan known as the "Section 399 plan," adopted November 2, 1976, shall continue in full force and effect, as amended by Measure "M" adopted on June 6, 1989. The Section 399 plan shall be governed and maintained in accordance with the provisions of former (1989) Charter Sections 399 through 444, as those sections are embodied in this article and as they were amended in Measure "M". (Prior code § 34.06.600)