15(1)In any case where—
(a)an individual makes a qualifying disposal or is the qualifying beneficiary in relation to a trustees' disposal, and
(b)relief has been (or falls to be) given under this Schedule in respect of an earlier disposal which was either a qualifying disposal made by the individual or a trustees' disposal in respect of which he was the qualifying beneficiary,
the amount which, apart from this paragraph, would be the amount available for relief on the disposal mentioned in paragraph (a) above shall not exceed the limit in sub-paragraph (3) below.
(2)In sub-paragraph (3) below—
(a)the disposal falling within sub-paragraph (1)(a) above is referred to as " the later disposal" ; and
(b)the disposal falling within sub-paragraph (1)(b) above or, if there is more than one such disposal, each of them is referred to as " the earlier disposal".
(3)The limit referred to in sub-paragraph (1) above is the difference between—
(a)the amount which would be available for relief on the later disposal if the qualifying period appropriate to that disposal (as redetermined where appropriate under paragraph 14 above) were extended by the addition of a period equal to so much (if any) of the qualifying period appropriate to the earlier disposal (or, as the case may be, to each of the earlier disposals) as does not already fall within the qualifying period appropriate to the later disposal; and
(b)the amount of relief given under this Schedule on the earlier disposal or, as the case may be, the aggregate of the relief so given on all the earlier disposals.
(4)References in this paragraph to relief given under this Schedule include references to relief given under section 34 of the [1965 c. 25.] Finance Act 1965 or section 124 of the [1979 c. 14.] Capital Gains Tax Act 1979 ; and—
(a)in relation to relief given under either of those sections paragraph (b) of sub-paragraph (1) above shall have effect as if, for the words from " which was" onwards, there were substituted " made by the individual"; and
(b)in the application of sub-paragraph (3) above where the earlier disposal was a disposal in respect of which relief was given under either of those sections, the reference in paragraph (a) to the qualifying period appropriate to the disposal is a reference,—
(i)if the disposal took place on or before 11th April 1978, to the period of ten years ending with the disposal; and
(ii)in any other case, to the qualifying period within the meaning of the section in question.