s 31 Exempt supplies ....
(1) A supply of goods or services is an exempt supply if it is of a description for the time being specified in Part 2 of Schedule 9 and it is not of a description specified in Part 3 of that Schedule .... (2) The Treasury may by order vary that Schedule by adding to or deleting from it any description of supply or by varying any description of supply for the time being specified in it, and the Schedule may be varied so as to describe a supply of goods by reference to the use which has been made of them or to other matters unrelated to the characteristics of the goods themselves. (3) The Treasury may by regulations make an exemption of a group 16 supply of a description specified in the regulations subject to conditions. (4) Regulations under subsection (3) may— (a) make different provision for different cases, and (b) make consequential or transitional provision (including provision amending this Act). (5) In subsection (3) “ group 16 supply ” means a supply falling within Group 16 of Schedule 9.