Cadency

In heraldry, cadency is any systematic way of distinguishing similar coats of arms belonging to members of the same family. Cadency is necessary in heraldic systems in which a given design may be owned by only one person (or, in some cases, one man) at once. Because heraldic designs may be inherited, the arms of members of a family will usually be similar to the arms used by its oldest surviving member (called the "plain coat"). They are formed by adding marks called brisures, similar to charges but smaller. Brisures are generally exempt from the rule of tincture.