CPC Binary Barcode is Canada Post's proprietary symbology used in its automated mail sortation operations. This barcode is used on regular-size pieces of mail, especially mail sent using Canada Post's Lettermail service. This barcode is printed on the lower-right-hand corner of each faced envelope, using a unique ultraviolet-fluorescent ink.
Read more about CPC Binary Barcode: Symbology Description, Generating Barcodes, Encoding Tables