(1) This section applies to a relevant employee (other than a prescribed employee) who is, or would, but for this section, be, a contributor to the Fund.
(2) If at any time the number of units of pension for which a relevant employee to whom this section applies would, but for this section, be required by section 20 to contribute to the Fund does not exceed the number of units of pension (including, where necessary, a fraction of a unit) determined by the Board to be the number of units of pension that would entitle that employee to benefits equivalent to the benefits to which he would be entitled under the superannuation scheme applicable to him immediately before the relevant date if he had continued to be a member of that scheme, the employee shall not be required or permitted to contribute to the Fund at that time in respect of units of pension.
(3) If at any time the number of units of pension for which a relevant employee to whom this section applies would, but for this section, be required by section 20 to contribute to the Fund exceeds the number of units of pension determined by the Board for the purposes of subsection (2) of this section, the employee shall not be required or permitted to contribute to the Fund at that time in respect of a number of units of pension greater than the excess.
(4) In the application of Division 2 of Part XA to and in relation to a relevant employee to whom this section applies, a reference in that Division to the number of units of pension for which he would, but for that Division, be required to contribute to the Fund shall be read as a reference to the number of units of pension ascertained by subtracting from the number of units of pension for which he would, but for this section and for that Division, be required to contribute to the Fund, the number of units of pension determined by the Board for the purposes of subsection (2).