PostBar, also known as CPC
4-State, is the black-ink
barcode system used by Canada
Post in its automated mail
sorting and delivery operations.
It is similar to other 4 State
barcode systems used by
Australia Post and the United
Kingdom's Royal Mail (from which
it derives), but uses an
obscured structure and encoding
system unique to Canada Post.
This particular bar code system
is used on "flats" (which are
of mail, such as magazines) and
4-State(PostBar) barcode is a barcode used by postal
services that consists of four barcodes of different heights
that can represent numbers and letters.
barcode is a variant developed on the basis of the circular
are mainly used in postal services and can indicate the starting
and ending location, category, date and other information of the
in different countries and regions use different barcodes, such
as the Intelligent Mail barcode in the United States, the Royal
Mail 4-State barcode in the United Kingdom, the Japan Post
barcode in Japan, etc.
origins date back to 1949, when Norm Woodland and Bernard Silver
invented the omnidirectional barcode symbology. Later, they
improved this symbol into a circular barcode, which was patented