By now, they are a common sight on chain restaurant menus found throughout New York City.

The little salt shaker inside the black triangle serves as a warning to consumers about how much sodium the entrée contains.

The city’s health department says the warnings are doing restaurant patrons a favor, but an industry group says the notations “confuse and mislead consumers.”

In the end, an appeals court in New York will decide.

Last month, appellate judges heard arguments on the use of the icons used as warnings about salty foods. Chain restaurants that have 15 or more locations anywhere in the country must put the icons next to any menu item with more than 2,300 milligrams of sodium. That’s roughly a teaspoon of salt and the daily limit suggested by the federal government.

The New York City Health Department originally implemented the rule in December 2015, but legal challenges delayed its enforcement until a court cleared the way in late May.

New York is being sued over the salt warnings by the National Restaurant Association, which calls the rule an “unlawful and unprecedented” mandate unfairly and unequally applied to food vendors.

The restaurant group also argues that the city Board of Health overstepped its authority by requiring the sodium warning.

Approximately 3,300 chain restaurants are subjected to the rule, which the city began enforcing in June, slapping penalties of $200 on violators.

As of Nov. 30, more than seven out of 10 restaurants inspected were found in compliance with the rule, according to health department figures.

In addition, 1,926 sodium inspections were conducted in 1,673 restaurants covered under the rule.

On Tuesday, the city launched a “Look Before You Eat” campaign to encourage its residents to look for the sodium warning icons on menus when they dine out.

The campaign will appear on television, in subway stations, online, bus shelters and on the side of city buses.

“You can’t tell how much sodium is in your food just by looking at it,” said New York City Health Commissioner Mary T. Bassett, M.D.  “New York City is the first city in the country to implement a sodium warning rule and give diners important information to protect their hearts when eating at chain restaurants. The goal is to help make the healthy choice the easy choice for all of us, and this icon does just that.”

Elevated sodium levels can lead to higher blood pressure, which is the leading risk factor for strokes and heart disease.

The sodium warning is among numerous health battles being waged in New York that have caught national attention. In 2006, the city voted to ban trans fats in restaurants. It also amended the health code to require chains to post calorie counts. In 2012, the city also proposed a ban on sugary drink sales larger than 16 ounces, but the state’s high court struck down the measure.