All examinations shall be free, impartial, and practical in their character, and shall deal with the duties and requirements of the position to be filled. They may include examinations of physical fitness and manual skill. Examinations shall be in charge of the chief examiner, except when a commissioner acts as examiner. The commission may call on other persons, either within or without the city service, to draw up, conduct, or mark examinations, and when such persons are connected with the city service, it shall be deemed a part of their official duty to act as examiners without extra compensation. In entrance and promotion examinations, the oral part shall not receive a mark exceeding one-fourth of the whole mark attainable in such examination. Honorably discharged soldiers, sailors, and marines, who have served as such in the Army, Navy, or Marine Corps of the United States, or in the National Guard of this State, shall be given full credit for their experience gained in such service, having due regard to the position for which the examination is held. As many examinations shall be held as may be necessary to provide eligibles for each grade of the service and to meet all requisitions and to fill all positions held by temporary appointees. From the return and report of the examiners, or from the examinations made by the commission, it shall prepare a list of eligibles for such grade. Such persons shall take rank upon the list in the order of their relative fitness as determined by the examination, without reference to priority of time of examination. The markings of all examinations shall be completed and the resulting eligible list posted within sixty days from the date of the examinations: Provided, That if the number of applicants taking the examination shall exceed one thousand, the time for completion of the markings and posting of the eligible list shall be extended by fifteen days, and shall be further extended by fifteen days for each additional thousand applicants who actually competed in the examination. The commission shall maintain a civil list of all persons in the classified service, showing, in connection with each name, the position held, the date and character of every appointment, and of every subsequent change in status. Each appointing officer shall promptly transmit to the commission all information required for the establishment and maintenance of said civil list. The commission shall keep minutes of its own proceedings. All minutes, examination papers, eligible lists, and other records of the commission, except as hereinafter specifically provided, as well as all recommendations and correspondence relating to applicants for office or employment received by the commission or by any officer having authority to make appointments, shall be preserved, and shall, subject to reasonable regulations as to the time of examination, be open to public inspection during ordinary business hours: Provided, however, That statements of former employers of applicants for office or employment shall be considered strictly confidential, and that these alone shall not be open to examination by any person not employed by the commission nor by such applicant even though employed by the commission.