Any power of the Treasury to make regulations or orders under this Act, except the power conferred by sections ... 181 and 192 shall be exercisable by statutory instrument subject to annulment in pursuance of a resolution of either House of Parliament.
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Where a power to make regulations or orders . . . is exercisable by the Treasury . . . by virtue of this Act, regulations or orders . . . made in the exercise of that power may—
(a) make different provision in relation to different cases or classes of case, and
(b) exclude certain cases or classes of case, and
(c) contain such transitional provisions as the Treasury thinks fit.
Regulations may provide that specified expressions, when used as described by the regulations, are to be given the prescribed meaning, notwithstanding that another meaning is intended by the person using them.
Any power conferred on the Treasury by this Act to make orders includes power to vary or revoke an order so made.