Section 68

In cases where a payment is covered by special authority a cer-tified copy of the authority shall be attached to the voucher. It is insuf-ficient to quote a reference to the authority. When a succession of payments is made under special authority it will, however, be suffi-cient to attach a certified copy of the authority to the first voucher of the series and to quote that Treasury payment voucher number on each subsequent relative voucher.