Section 37B(1)(iii) in The Coal Mines Provident Fund Scheme
(iii)Contribution cards in Form 'X' or Form 'Y' annexed hereto, as the case may be, in respect of any period of currency commencing on or after 1st April, 1972, where the member is eligible to join the Coal Mines Family Pension Scheme under paragraph 3 of the Pension Scheme].