(1) In this section, references to a distribution or distributions shall not include references to a distribution or distributions -
(a) made before the 9th day of February, 1983, or
(b) treated under this Chapter as not being a distribution or distributions for the purposes of this section.
(2) Where in any accounting period a company receives a distribution, the company shall not be liable to pay advance corporation tax in respect of distributions made by it in that period unless the aggregate amount of the tax credits in respect of the distributions made by the company in the period exceeds the aggregate amount of the tax credits in respect of distributions received by it in the period.
(3) Where in any accounting period there is an excess referred to in subsection (2), the amount of advance corporation tax payable by the company in respect of distributions made by it in that period shall be equal to the excess.
(4) Where the aggregate amount of the tax credits in respect of di