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"The canton is a square part of the escutcheon, usually occupying about one-eighth of the field; it is placed over the chief at the dexter side of the shield: it may be charged, and when this is the case, its size may be increased. The canton represents the banner of the ancient Knights Banneret. The canton in the example is marked A." -Hall, 1862

Canton Ordinary

"The canton is a square part of the escutcheon, usually occupying about one-eighth of the field; it…