Section 202(2) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(2)(a)This regulation shall apply to Commissioned Officers both Permanent and Short Service, in all Branches except officers of the Army Medical and Army Dental Corps seconded to the Navy.(b)This regulation shall not affect the position of officers already holding acting ranks granted otherwise than for the duration of a specific appointment under any orders of a competent authority made before the commenement of these regulations except that their reversion to their confirmed rank shall be governed by the provisions of sub-regulation (9).(c)Acting promotion of officers of the Army Medical and Army DentalCorps seconded to the Navy shall continue to be regulated under therules applicable to their respective Corps.Grant of acting ranks