It is the same with man-made signs. These signs point to something beyond themselves by convention—that is, by people investing these signs with meaning. Traffic signs are a good example of man-made signs. A red octagon standing on an eight-foot post signifies that we must stop. There is nothing about the color or shape of the sign that inherently means stop. The sign communicates to us that we should stop simply by convention; that is, the traffic laws invested the sign with a particular meaning: