C4.—(1) Subject to regulations C5 to C7 and C27, a member shall, at such intervals as the appropriate administering authority may determine, make contributions in respect of every employment in relation to which he is a member—
(a)in the case of a manual worker, at the rate of five per cent. of his remuneration in the employment, and
(b)in the case of an officer, at the rate of six per cent. of that remuneration.
(2) In this regulation—
“officer” means an employee whose duties are wholly or mainly administrative, professional, technical or clerical; and
“manual worker” means an employee who is not an officer.