Any power conferred by any provision of this Act to make an order . . . F1 shall be exercisable by statutory instrument.

Any power conferred by this Act to make an order . . . F3 shall include power to make such incidental, supplemental or transitional provision as the authority exercising the power thinks fit.

Any power conferred by any provision of this Act to make an order . . . F4 shall include power to revoke or vary the order by a subsequent order made under that provision.