The Cuban government has announced that the guayabera - the roomy cotton or linen shirt - is now the country's official formal dress garment.
Male officials at state functions are now required to wear white guayaberas, with long sleeves and pockets in front, and two pleats both front and back.
Women's versions can vary in colour and style.
The guayabera shirt has long been popular in Cuba, as well as other Latin American and Caribbean nations.
It is also often worn in parts of Florida and in Puerto Rico, where it is part of the national costume for men.
The origins of the shirt are disputed in the region. One Cuban legend says it was first made in the early 1700s on the banks of the Yayabo River, for immigrant agricultural workers who needed large pockets to hold enough cigars to get them through a day's work.
Among other theories is that it originated much earlier in Mexico's Yucatan peninsula.
The shirt is traditionally made of cotton or linen and it is worn untucked, so is cool in hot weather.
The Foreign Ministry formulated the resolution on the guayabera earlier in the year but it has just been published into law.
The resolution says guayaberas "have been worn with pride and satisfaction" by Cubans of all backgrounds, "evolving from their rural roots to reach various sectors of the urban population".
President Raul Castro already often wears guayaberas for public occasions, as do many other Cuban officials.