(a) The secretaries shall act as joint secretaries at all meetings and hearings of the Commission. The secretary of the section of the Commission of the country in which a meeting or hearing is held shall prepare a record thereof and each secretary shall preserve an authentic copy of the same in the permanent offices of the Commission.

(b) Each secretary shall receive and file all applications, references and other papers properly presented to the Commission in any proceeding instituted before it and shall number in numerical order all such applications and references; the number given to an application or reference shall be the primary file number for all papers relating to such application or reference.

(c) Each secretary shall forward to the other for filing in the office of the other copies of all official letters, documents, records or other papers received by him or filed in his office, pertaining to any proceeding before the Commission, to the end that there shall be on file in each office either the original or a copy of all official letters and other papers, relating to the said proceeding.

(d) Each secretary shall also forward to the other for filing in the office of the other copies of any letters, documents or other papers received by him or filed in his office which are deemed by him to be of interest to the Commission.