When the Commission has established a list of eligible candidates for promotions or for new positions in the Police Department, appointment to any position shall be made of 1 of the 3 candidates given the highest ratings by the Commission or its examiner; provided, however, that on demotions for retrenchment or any other but disciplinary reasons the persons above entrance grade shall not lose their seniority.
(Prior Code, § 2.01, Subd. 7)