Square Number Plates
Motorcycle Number Plates
They can fit the license plate holes of many household cars and trucks.
This enables manufacturers of license plates around the world to reap the benefits of economies of scale.
The reason is that when you buy a screw that is bigger or smaller than the existing hole, you would have wasted your money, and no one likes that.
The officials also asked bikers to carry brass watch fobs that bear their registration information.