Section 202(13)(b) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(b)Furlough. - An officer holding acting rank who proceeds on furlough shall retain his acting rank if under these regulations he is entitled to retain the acting rank during the period of annual leave :(i)When furlough is taken by itself;(ii)When furlough is combined with annual leave.