If a receipt can be brought on a pending file it should be brought on that file; otherwise a new case file should be opened, numbered and entered in the index of case files. The number of the major head, the minor head and the case file to which it belongs shall be noted in each letter in red ink under the serial number. The file should then be put up with papers if any, which will be required for reference in disposing of it. To avoid multiplication of case files great care should be taken in opening new case files. The serial number of the case file with major and minor heads on which each document received during the day has taken shall be entered in column 7 of the Correspondence Register. No case file shall be opened for papers of an ephemeral nature and no reminders shall be filed in case files. Papers of an ephemeral nature and reminders shall be put up on routine note sheets.
