Unless their appointments are renewed pursuant to the provisions of Section 10.105, the employment of all provisional employees, appointed under the Charter of 1932, whose appointment does not meet the provisions of this Charter, shall be terminated within three years of the operative date of this Charter in accordance with the rules and regulations governing layoffs. Such provisional employees may qualify for certification as eligibles under rules and regulations expressly authorized by civil service rules approved by the Board of Supervisors. Such rules may establish special credit for civil service examinations for years of service or, through other methods, recognize the service of such employees who have held such employment for more than six months at the operative date of this Charter.