Mandatory sign

A mandatory sign is like when your mom tells you to clean your room. It is a sign that tells you that you MUST do something. It is usually in the shape of a circle with a white background and a blue border. Inside the circle, there is a picture or symbol that shows what you have to do, like wear a helmet, use a certain exit, or wash your hands.

So, just like your mom's rules, the mandatory sign is a rule that you cannot ignore. You have to follow it to stay safe and avoid getting into trouble. So, anytime you see a sign with a white circle and blue border, remember it is telling you something important that you should do.