When a third part of the top of a shield is marked off by a horizontal line it forms what is called a Chief, and when the top left-hand corner is marked off as a small square, measuring about a third of the chief, it is called a Canton, and is often an honourable augmentation to a coat-of-arms, granted for some distinguished service.
When a shield has a narrow border all round it, it is called a Bordure, and this is also often an honourable augmentation, difference, or mark of cadency on a family coat-of-arms.
The boundary lines of all these charges are normally straight, but they may also be either
Engrailed
Embattled
