New York City’s new warning labels for salt-laden, chain-restaurant food is headed for a court fight. The National Restaurant Association filed a lawsuit in Manhattan on Thursday; two days after the rule took effect. The association says the warning will confuse and mislead consumers, and oversteps the city’s authority. The rule requires chain restaurants to put a salt shaker icon on menu items that top the recommended daily limit of 2,300 milligrams of sodium. New York is no stranger to lawsuits regarding healthy-eating measures. Courts struck down a size limit on sugary drinks but upheld a requirement for chain eateries to post calorie counts on menus.