What is one requirement for straight ladders regarding their extension above support?

For straight ladders, a critical safety requirement is that they must extend at least 3 feet above the upper support point. This extension is important as it provides stability and allows the person using the ladder to maintain a secure grip when transitioning on and off the ladder. The additional height ensures that the user can safely navigate the gap between the ladder and the structure they are accessing, significantly reducing the risk of falling. This safety standard is emphasized in various guidelines and regulations concerning ladder use to promote best practices and safe working conditions.