New Delhi, July 7: The navy expects actor Akshay Kumar to "hoist the gin pennant" and invite its officers for a drink after the star was pictured wearing his rank wrongly for a forthcoming movie.

The navy itself may have erred, however, because nearly all films featuring the armed forces are supposed to be vetted by the military.

The military usually appoints an officer from the relevant service as an adviser on matters such as uniforms, ranks and badges.

In the navy tradition the officer wearing the uniform wrongly - such as missing a loop in the waist belt or, as in the case of Akshay in Rustom, wearing the rank incorrectly - must invite those who have corrected him for drinks.

This is done at sea by a ship hoisting a "gin pennant", a flag that invites other ships' companies to join for drinks aboard after they have docked.

In Akshay's case, his character, Commander Rustom Pavri - loosely adapted from a celebrated case from 1959 that involved a real-life naval officer, Commander Kawas Manekshaw Nanavati - has worn the Nelson's Ring on his epaulettes the wrong way.

The navy commander's rank insignia features two golden ribbons as stripes and the Nelson's Ring, also simply called the Nelson. The Nelson is a braided ribbon. In braiding the ribbon, officers have to ensure that the shorter end faces the front.

All officers' ranks feature the Nelson's Ring, named after Admiral Horatio Lord Nelson, the British commander of naval forces in the Napoleonic wars.

Akshay was preparing for his role through the past year. In February this year he was present at the International Fleet Review of Visakhapatnam where he was on the same boat as Prime Minister Narendra Modi.

The navy had justified Akshay's presence at the event by calling him its "Brand Ambassador" but had later withdrawn that description.

Akshay had also entertained guests at the wedding of the son of Admiral Robin Dhowan who retired as the Chief of Naval Staff on May 31 this year. With such recent proximity to the service he will represent in his film, the actor was expected to be better acquainted with the peculiarities of the service in which officers have to maintain 16 or more (depending on rank) types of uniforms, most of them for ceremonial purposes.

The colonial legacy sits heavy on the service's shoulders and the navy is not exceptional in this but it has more peculiarities than the army and the air force.

It is in depicting one of these colonial legacies - the Nelson's Ring - that Akshay has made a mistake. The loop of the ribbon that makes the "ring" should have its shorter end in the front of the epaulette. In the pictures for Rustom, Akshay's Nelson has the longer end in front.

Akshay's character Rustom Pavri is said to portray Commander Nanavati who is regarded as a hero in the navy despite his "crime of passion" that kept a generation transfixed.

The murder case is also a landmark in the judicial history of the country because it was the last of the jury trials.

Nanavati, who was second-in-command of the INS Mysore that used to be based in Bombay's Western Naval Command, used to go for frequent sailings. This left his English-born wife, Sylvia, often lonely.

In April 1959, his wife confessed to him that she had an affair with a family friend who was a flamboyant businessman, Prem Ahuja.

Nanavati, who was then 37, took his wife and children to a cinema, drove to the armoury in the naval base and got his service pistol issued citing official reasons. After work he went to Ahuja's house and killed him with three shots. Subsequently, he went to the Provost Marshal in the naval base and confessed his crime. On the advice of the Marshal he surrendered to police.

One story goes that before killing Ahuja, Nanavati asked him if the businessman was willing to marry Sylvia and adopt their children. Ahuja is alleged to have replied disparagingly. This angered Nanavati, who pulled the trigger.

Nanavati served three years in prison before being acquitted after a high court overturned his punishment. In the course of the trial, the Indian judiciary transited from jury trials to the bench system. The Nanavati family later emigrated to Canada.

Sunil Dutt's Yeh Rastey Hain Pyaar Ke was also loosely based on these events. Dutt had portrayed an air force officer.