1993 Cadillac DeVille Owner's Manual - Page 183

/ An OCTAGONAL (eight-sided) sign means STOP. It is alwaysred with white letters. A DIAMOND-shaped sign is a warning of something ahead -for example, a curve, steep hill, soft shoulder, or a narrow bridge. A TRIANGLE, pointed downward, indicates YIELD.It assigns the right-of-way to traffic on certain approaches to an intersection.