Section 68(6) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(6)The use of the above Flag Plates and Discs is as follows :(a)The Red Disc shall be displayed on formal occasions when the Flag Officers and Commodores who are entitled to wear a Broad Pendant, are proceeding on duty, and when the full ceremonial, laid down in Regulations 82 to 84, is not required.(b)The Blue Disc shall be displayed on formal occasions when non-executive officers of Rear-Admiral's rank and above, and Commodores not entitled to wear a Broad Pendant, are proceeding on duty.(c)The White Disc maybe used on informal occasions by the Senior Officers in clauses (a) and (b). When this disc is shown, only courtesy salutes shall be accorded.
