Cal. Education Code § 45280

The commission shall, by rule, provide for an open competitive examination and a promotional examination to be held at the same time for the position of business manager or for any other single position class which it declares to be at or above the level of business manager. It shall require that all educational and work experience requirements be developed to fit the needs of the position in such a manner that the position will attract competent and qualified applicants from within the classified service, among certificated personnel, or other persons meeting the minimum requirements established for the position. Such rule shall provide: (a) that all permanent employees of the district, classified and certificated, who meet the established minimum qualifications, shall be eligible to compete in the examination as promotional candidates; (b) that promotional credits, including seniority credits, if any, shall be equally applicable to both classified and certificated promotional candidates; (c) that eligibility lists resulting from such an open competitive and promotional examination shall be merged according to the order of the examination scores into a single eligibility list, after the scores of each candidate on the promotional list have been adjusted for promotional credits, including seniority credits, if any; and (d) that the examination for any such position shall not be construed to be an entrance level position examination.