(1)This section sets out the categories of index referred to in section 517(1).
(2)Category 1 is the retail prices index.
(3)Category 2 is any general index which—
(a)is similar to the retail prices index, and
(b)is published by the government of any foreign state or an agent of such a government.
(4)Category 3 is any published index of prices of shares listed on a recognised stock exchange.