4. An officer shall not be entitled to make application under regulation 3 of these regulations—
(a)unless either—
(i)his employment since the date of his first entry into public health service employment after war service is reckonable as contributing service under the principal regulations (not being contributing service which is reckonable in consequence of additional contributory payments or payments for added years under regulation 23A(2) of the principal regulations or as a result of his having received and not repaid a return of his superannuation contributions); or
(ii)on his first entry into public health service employment after war service he became subject to a pension scheme providing benefits under a policy of insurance, and after leaving that employment, or any subsequent public health service employment in which he was subject to a pension scheme providing benefits under a policy of insurance, he entered public health service employment which reckons as contributing service under the principal regulations (not being contributing service which is reckonable in consequence of additional contributory payments or payments for added years under regulation 23A(2) of the principal regulations or as a result of his having received and not repaid a return of his superannuation contributions) without a break of 12 months or more between consecutive periods of any such employment; or
(b)for war service which, apart from these regulations, already falls to be taken into account in the calculation of any pension under the principal regulations or which he had reckoned or has previously had an opportunity to reckon under another scheme for the provision of retirement benefits.