Section 202(14)(v) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(v)an officer holding acting rank who, on completion of a course of ten weeks' duration or more, proceeds to attend a course of less than ten weeks' duration without having joined his ship or establishment, shall continue to retain his acting rank, provided that the holder of the acting rank will be allowed this concession only if he is reabsorbed in the establishment of his ship or establishment in the same rank on completion of the first course.