"The specific requirements of the service as to ... space required ... at stations, fixtures, furniture, etc., will at all times be determined by the Post Office Department and made known through the General Superintendent of Railway Mail Service." Section 1186, third paragraph. "Railroad companies will require their employees who handle the mails to keep a record of all pouches due to be received or dispatched by them, and to check the pouches at the time they are received or dispatched, except that no record need be kept of a single pouch from a train or station to the post office or from the post office to a train or station which, in regular course, is the only pouch in the custody of the company's employees at that point while it is being handled by them. This is not to be construed as relieving railroad companies from having employees on trains keep and properly check a record of all closed pouches handled by them, without exception." Section 1187, first paragraph. "In case of failure to receive any pouch due, a shortage slip should be made out, explaining cause of failure, and forwarded in lieu of the missing pouch. Specific instructions in regard to the use of shortage slips will be given by the General Superintendent of Railway Mail Service." Section 1187, second paragraph. "Every irregularity in the receipt and dispatch of mail should be reported by the employee to his superintendent promptly, and if a probable loss of or damage to mail is involved, or if the cause of failure to receive a pouch is not known, the report should be made by wire, and the superintendent will notify the division superintendent of Railway Mail Service without delay. A copy of the employee's report should be attached to and become a part of the permanent pouch record." Section 1187, third paragraph. "Train pouch records will be kept on file at the headquarters of division superintendents of railroad companies for at least one year immediately following the date the mail covered by them was handled, and shall be accessible there to post office inspectors and other agents of the Post Office Department. Station pouch records will be kept on file at the station to which they apply for at least one year immediately following the date the mail covered by them was handled, and shall be accessible there to post office inspectors and other agents of the Post Office Department." Section 1187, fourth paragraph. "Railroad companies will require their employees to submit pouch records for examination to post office inspectors and other duly accredited agents of the Post Office Department upon their request and exhibition of credentials to such employees." Section 1187, fifth paragraph.