PARIS — In the days after terrorists massacred scores of people lounging in Paris cafes on an unseasonably warm November night in 2015, Parisians defiantly returned to their neighborhood bistros in droves to show that they would not be broken.

The hashtags #jesuisenterrace, meaning “I am outside,’’ and #tousaubistrot, or “Everyone to the bistro,’’ exploded on social media, as people gathered to lift a glass of wine under the heat lamps as a way to demonstrate that their way of life would continue.

“It was a sign of their power and resilience,’’ said Olivia Polski, an assistant mayor for commerce in Paris.

Now, a coalition of bistro owners, unions, and trade organizations is lobbying to get UNESCO to grant Paris’s sidewalk bistros and cafes official status as France’s “intangible cultural heritage.’’

For many tourists and French citizens, Paris would not be Paris without its local bistros and sidewalk cafes. Whether small or sprawling, they are inseparable from the city’s iconic image — immortalized in Hollywood movies and novels.

But are they among the world’s intangible cultural heritage? For Alain Fontaine, a bistro owner and president of the association pushing the UNESCO idea, the answer is an emphatic “yes.’’

“For centuries, they have been melting pots, places where people of different ethnicities, professions and social classes mix,’’ said Fontaine, who owns Le Mesturet, an old-fashioned bistro with a zinc bar and chandeliers made of wine bottles.

Support for the cause has come from Parisian actors, writers, and residents for whom their local cafes and bistros represent a way of life. Many attended a news conference this past week at Le Mesturet to explain the rationale.

The bistros and cafes are not just places to sip an espresso and people-watch or to have a meal with a glass of wine. They can be arenas for robust debate, offices to seal deals or places to woo a romantic interest.

For many who live in cramped city apartments, the cafes are an extension of home — the living room around the corner, a space both public and private.

“I have clients who met their spouses here,’’ Fontaine said. “I raised my children here.’’

The “intangible cultural heritage’’ label is a relatively recent addition to the basket of titles for extraordinary human and natural creations granted by UNESCO, the United Nations cultural organization.

The designation was intended to recognize practices, events, and crafts that are not physical sites but that are still a unique part of a country’s cultural heritage.

Since 2008, when the program started, UNESCO has designated some 451 intangible cultural heritage entities in the world, and 14 are in France. Among them: an elaborate lace-making technique in Normandy, the summer solstice fire festivals in the Pyrenees, and folk dances in Brittany.

In other countries, the status has been awarded to Kabuki theater in Japan, the manufacture of batik cloth in Indonesia and the pre-Inca tradition in Peru of specialized judges who determine water rights.

But the road to protected status from UNESCO can take at least a couple of years — sometimes longer. French candidates must be preselected by the Culture Ministry before being passed on to UNESCO for review. Those campaigning for the bistros and cafes hope to make the list in 2020.

The UNESCO designation has occasionally drawn criticism because of the vagueness of the term and because some say it is used to promote tourism and consumption rather than to encourage the study and preservation of local traditions and practices.

When it comes to the Paris bistros and cafes, it may be hard to explain why they should be designated part of France’s cultural heritage but not those on the Côte d’Azur or in the wine center of Bordeaux.

But Fontaine and his supporters, as well as the Paris mayor’s office, which is backing the effort, point to the central role that bistros and cafes played after the 2015 attacks.

People returned to the establishments soon after the assaults, in a demonstration that in times of crisis or celebration, Parisians need their local bistros.

“Bistros were attacked because they are symbols of French culture and life,’’ Polski, the assistant mayor, said. “It hit us hard, because we all have treasured memories in bistros.’’

Fontaine’s group is up against some tough competition in France. The “bouquinistes,’’ sellers of old books and other printed material on the banks of the Seine, are also seeking the UNESCO designation.

So, too, are the makers of that most recognizable of French bread, the baguette, who say it deserves the title.