86.—(1) The power to make an order conferred by section 7 of the Bankers' Books Evidence Act 1879(1) may be exercised for the purposes of a court-martial—
(a)during investigation of any offence and before the accused is notified that he is to be tried by court-martial, by the commanding officer of the accused; and
(b)at preliminary proceedings and during the court-martial, by the judge advocate.
(2) The order shall be in the form set out in Schedule 2 to these Rules.