8(1)In this Schedule—
(a)references to the register are references to the register maintained under section 24 of this Act;
(b)references to registering a person are references to registering him in that register; and
(c)references to a person’s registration are references to his registration in that register;
and “unregistered” shall be construed accordingly.
(2)For the purposes of this Schedule a person carries out a taxable activity if a quantity of aggregate is subjected to commercial exploitation in the United Kingdom in circumstances in which he is responsible for its being so subjected.