Example of border.
In heraldry, the honorable piece that surrounds the inside of the shield on all sides is called a border. Its width is equal to one sixth of the total of the shield.
The border is, after the lambel, one of the most used heraldic pieces as brisura to differentiate the blazons of different branches belonging to the same lineage or different armories within the same branch.
The border whose thickness is reduced, is known as filiera. The piece that surrounds the interior of the shield, but without touching its edges, receives the name of border. The border is a symbol of protection, favor and reward. The border is a particular concession of the king of Spain, so it is more common to see it in many families of these kingdoms where it is not strictly observed to take it by brisura or piece of distinction of the simple arms of a family among the children of her, which is its most general significance. And in this sense Philip V was used as Duke of Anjou, putting it by brisura which is the difference in the arms of one of the sons of the royal house of France as each of them distinguishes itself with other brisuras diverse. The border, not being brisure, is a symbol of protection, of favor and of reward, serving as a reparation to those whom the princes want to secure in their favor against their enemies, although formerly it represented nothing more than the coat of arms of the knight, conceding this piece of honor to the brave warriors who took from the combat stained their dress or quota of arms of the blood of the enemies. Example of a serrated edge (in the lower half).
As a heraldic attribute, the border receives different grades as composite, denticulate, cut, quartered, squared, rounted, split, plywood, beaded border or piece border.
Heraldic Glossary, Armor.
wiki
