Section 75(1) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(1)Indian Merchant ships may wear the Indian Blue Ensign plain and under faced, consisting of a Royal Blue Flag, the width being one half of the length and the National Flag of India superimposed in the top quarter next to the Staff, provided the following conditions are fulfilled:(a)The officer commanding the ship must be an officer on the retired or emergency list of the Indian Navy or an officer of the Indian Naval Reserve.(b)The crew must include (in addition to the Commanding Officer) officers of the Indian Naval Reserve to the number specified from time to time by the Chief of the Naval Staff, but officers on the retired or emergency list of the Indian Navy may be included in the number specified.(c)Before hoisting the Blue Ensign, the officer commanding the ship must be provided with a warrant issued by the Chief of the Naval Staff.(d)The fact that the Commanding Officer holds a warrant authorising him to hoist the Blue Ensign must be noted on the ship's articles of agreement.
