The Council of the District of Columbia is authorized to provide by regulation for the rental of portions of public space on or above the surface of the pavement or the ground, as the case may be, and not actually required for the use of the general public, for such period of time as the said space may not be so required or for any lesser period; provided, that nothing herein contained shall be construed as requiring the Council to require the payment of rent as a condition to the use of public space: (1) in accordance with the provisions of regulations promulgated under the authority of § 6-404; (2) by a public utility company for the installation and maintenance of any of its equipment or facilities, under permit issued by the District; or (3) for the sale of newspapers of general circulation; provided further, that the proposed rental of public space within the area of the District of Columbia subject to the provisions of §§ 6-611.01 and 6-611.02, if the proposed rental of public space entails the erection or alteration of the exterior of a building, shall be submitted to the Commission of Fine Arts in accordance with the provisions of §§ 6-611.01 and 6-611.02. The regulations adopted by the Council of the District of Columbia shall provide that public space rented under the authority of this part shall be rented only to the owner of property fronting and abutting such public space; that any person using such space shall not acquire any right, title, or interest therein; that both the United States and the District of Columbia, and the officers and employees of each of them, shall be held harmless for any loss or damage arising out of the use of such space, or the discontinuance of any such use; that the Mayor may require such space to be vacated upon demand by him and its use discontinued, with or without notice, and with no recourse against either the United States or the District for any loss or damage occasioned by any such requirement; and that if any such use be not discontinued by the time specified by the Mayor, the said Mayor may remove from such space any property left thereon or therein by any person using such space under the authority of this part, at the risk and expense of the owner of the real property abutting such space.