A heraldic badge, an emblem, an impresa, or device, or personal device worn as a badge indicates allegiance to, or the property of, an individual or family. Medieval forms are usually called a livery badge, and also a cognizance. They are para-heraldic, not necessarily using elements from the coat of arms of the person or family they represent, though many do, often taking the crest or supporters. Their use was more flexible than that of arms proper, and it has been suggested that escape from the increasing rigidity of heraldic regulation was a major reason for their popularity.