(a) The offices of the City Clerk and the offices of all directors of departments, of all commissioners or chiefs of divisions and of all heads of bureaus and offices under the Mayor, all of the commissions appointed by Council and of all other boards or commissions of the City, but not the office of the Mayor, shall be offices of public record. Each such office shall preserve, file, record and index in proper form, all official documents and formal reports received by it pertaining to the duties assigned to it, and not required to be transmitted to another office of the City. They shall likewise preserve, file, record and index properly authenticated copies of all official documents and all formal reports issued by them.
(b) Any official document received by any such office and not pertaining to the duties or functions of such office shall not be retained, filed or indexed in such office, but shall be transmitted immediately to the appropriate office, or to the office of the Mayor. Boards and commissions or other authorities which do not maintain offices shall be deemed, for the purposes of this section, to be a part of and included within such offices in the administrative service as they may be most nearly affiliated with, as designated by ordinance or by the Mayor.
(c) All the documents and records covered by provisions of this section shall be the property of the City and shall not be removed from their respective offices except for proper use, and shall be returned upon the completion of any such use. Private papers, not pertaining to the business of any office, shall not be filed or recorded among its records. The official documents and records of any office shall, during the hours when such office is open, be under proper regulations and conditions open to examination by all persons whose official duties so require and to all citizens or taxpayers of the City who may so request. However, documents, reports and records not yet completed, or in use in the work of the office, or documents or records containing information which is required in evidence in litigation in which the City is interested, or which if revealed would result in injury to the interests of the City in litigation or in the conduct of the City’s business, need not be so revealed.