PARIS — In the days after terrorists massacred scores of people lounging in Paris cafes on a November night in 2015, Parisians defiantly returned to neighborhood bistros 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 to show 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, Paris would not be Paris without its local bistros and sidewalk cafes. 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 «yes.»

«For centuries, they have been melting pots, places where people of different ethnicities, professions and social classes mix,» said Mr. Fontaine, who owns Le Mesturet, an old-fashioned bistro.

Support for the cause has come from actors, writers and residents for whom local cafes and bistros represent a way of life. These are not just places to sip an espresso or to have a meal. For many who live in cramped city apartments, they are an extension of home — the living room around the corner, a space both public and private.

The «intangible cultural heritage» label is a relatively recent addition to the titles granted by Unesco, the United Nations cultural organization. The designation was intended to recognize practices, events and crafts that are not physical sites but 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 15 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.

French candidates must be preselected by the Culture Ministry before being passed on to Unesco for review.

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 preservation of local traditions and practices.

Mr. 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.

«Bistros were attacked because they are symbols of French culture and life,» Ms. Polski said. «It hit us hard, because we all have treasured memories in bistros.»

Calls to recognize a center of life andsymbol of defiance.