The city's Dabbawallas, who had once caught the fancy of Prince Charles for their super-efficient tiffin-delivery system, today shared the tricks of their trade with US Commerce Secretary Gary Locke.

Locke met the Dabbawallas near Churchgate station (where they gather daily before delivering tiffin boxes to their clients) and had a chat with them about how they function.

"We explained to him our modes of delivering tiffins: by trains, bicycles or carts, because we do not believe in using modern methods or technology. We also explained our unique colour code system which ensures tiffin boxes reach the correct destinations, without confusion or delay," said Sopan Mare, president of Nutan Mumbai Tiffin Box Suppliers.

Around 5,000 dabbawallas deliver tiffins to over two lakh clients across Mumbai every day.

Mare presented Locke with a shawl and a bouquet. The US secretary also posed for photographers holding two dabbas, and wearing a white topi which Dabbawallas don.

Locke, along with a delegation of representatives of 24 US companies, is currently on a visit to India.