single source requirement
single-source requirement. Under the common-law tort of false advertising, the necessity to show that the plaintiff is the only supplier of the genuine goods in question and that buyers would have bought the plaintiff’s goods if the true nature of the defendant’s goods had been known. Ely–Norris Safe Co. v. Mosler Safe Co., 7 F.2d 603 (2d Cir. 1925). • This is a narrow exception to the common-law rule that the tort of false advertising applies only in instances of passing off, trade defamation, and trade disparagement.