SECTION I. No crates, barrels, or packing cases will be permitted to remain upon the exhibition space after their contents have been removed, except upon the recommendation of the chief of the department where the exhibit is installed, approved by the director of exhibits. SEC. II. The Exposition Company will provide a storage warehouse for crates, barrels, and packing cases, under a reasonable schedule of charges based upon those levied by similar warehouses, which it will be optional for exhibitors to use. SEC. III. Facilities for the conveyance of empty crates, barrels, or packing cases to storage places will be provided at a moderate price. ARTICLE XVII. SECTION I. No exhibit or object upon exhibition may be sketched, copied, or reproduced in any way whatever without the permission of the exhibitor, approved by the director of exhibits, except that the president of the company may give such permission. ARTICLE XVIII. SECTION I. Exhibitors desiring to contract for service of electricity, steam, compressed air, power from shafting, gas, or water, must make application to the chief of the department in which their exhibits are installed. No application for service will be entertained unless made upon a blank furnished by the director of works, which may be obtained from a chief of a department, and when an application for service has been approved by the director of exhibits the contract will be executed on the part of the Louisiana Purchase Exposition Company by the director of works on terms and conditions that will be stated in each case. The director of exhibits and the director of works, in their discretion, are authorized to furnish gratuitously to exhibitors a limited amount of power for the operation of machines and processes. The character of the exhibit requiring power for its operation will have much to do with determining the amount of power that will be furnished gratuitously. ARTICLE XIX. SECTION I. Concessions may be granted for private exhibitions for which a charge for admission may be made; for restaurants, for places of amusement, for merchandising, and for other purposes not incompatible with the scope and dignity of the exposition, under terms and conditions to be determined upon by the proper authorities in each case. ARTICLE XX. SECTION I. An official catalogue of all exhibits will be published in English by the Exposition Company. Foreign governments and the governments of the States, Territories, and Districts of the United States, making a collective exhibit, may publish separate catalogues of their own exhibits when recommended by the director of exhibits to the president and approved by him. SEC. II. The sale of catalogues is reserved exclusively by the Exposition Company. ARTICLE XXI.