Gas companies shall, on and after January 1, 1961, keep their books and accounts in accordance with the rules, definitions and instructions herein set forth and the Rules and Regulations of the Department.
The entries to the accounts shall be supported with all necessary facts pertaining thereto, with identifying references to the records, contracts, pay rolls or other original books or memoranda upon which the same are founded. All books of account, pay rolls, records, contracts, vouchers and original books and memoranda relating to the financial affairs of the companies shall be readily accessible for examination by representatives of the Department.
Manufacturing companies in which the manufacture and sale of gas is a minor portion of the business, or persons engaged in such business, shall be required to keep books and accounts of the transactions relating to their gas business only.
Each utility may adopt such plan of account numbers as it deems appropriate; provided, however, that it shall keep readily available a list of the account numbers and sub-divisions of accounts which it uses and a reconciliation of such numbers and sub-divisions with the account numbers and titles provided herein.
220 CMR, 50, 1