Section 329(6)(b) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(b)If a sailor is transferred to another ship while in prison or detention or in the second class for conduct, the date of recommencement of "Very Good" conduct will not be known and the words "not V.G." shall be inserted in the appropriate column of his Recommendation for [Promotion] [Substitued by S.R.O. 361, dated 10th November, 1975] and Conduct Record Sheet.