PostBar
Encyclopedia
PostBar, also known as CPC 4-State, is the black-ink barcode system
Barcode system
A barcode system is a network of hardware and software, consisting primarily of mobile computers, printers, handheld scanners, infrastructure, and supporting software. Barcode systems are used to automate data collection where hand recording is neither timely or cost effective...

 used by Canada Post
Canada Post
Canada Post Corporation, known more simply as Canada Post , is the Canadian crown corporation which functions as the country's primary postal operator...

 in its automated mail
Mail
Mail, or post, is a system for transporting letters and other tangible objects: written documents, typically enclosed in envelopes, and also small packages are delivered to destinations around the world. Anything sent through the postal system is called mail or post.In principle, a postal service...

 sorting and delivery operations. It is similar to other 4 State barcode systems used by Australia Post
Australia Post
Australia Post is the trading name of the Australian Government-owned Australian Postal Corporation .-History:...

 and the United Kingdom's Royal Mail
Royal Mail
Royal Mail is the government-owned postal service in the United Kingdom. Royal Mail Holdings plc owns Royal Mail Group Limited, which in turn operates the brands Royal Mail and Parcelforce Worldwide...

 (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 larger-than-letter-size pieces of mail, such as magazines) and parcels.
This symbology
Symbology
Symbology concerns the study of symbols.Symbology may also refer to:-Academics:* Semiotics, study of signs and symbols* Iconography, branch of art history which studies images...

, derived from the RM4SCC
RM4SCC
RM4SCC is the name of the barcode symbology used by the Royal Mail for its Cleanmail service. It enables UK postcodes as well as Delivery Point Suffixes to be easily read by a machine at high speed....

 system used by the British Royal Mail, uses a series of bars, each of which can individually have one of four possible states, to encode information used in automated sortation and delivery onto each piece of mail. Each bar can either be short and centred (known as a tracker), medium and elevated (an ascender), medium and lowered (a descender), or full height. This symbology also uses an element known as a Data Content Identifier (or DCI), which specifies what types of information are encoded into each barcode, such as postal codes, customer information, and exact delivery points. The information that goes into each barcode is obtained from the address printed on the front of the envelope it is ultimately printed on, as well as the physical dimensions of each piece of mail. This code also uses a Reed-Solomon error correction technique, so that in case a particular piece of mail is mishandled, the information encoded in the barcode can still be correctly decoded.

Character sets

Four character sets are used in PostBar codes, known as "A", "N", "Z" and "B" characters. Three-bar A characters are used exclusively to encode letters, and two-bar N characters encode only digits. Three-bar Z characters can encode either letters or digits. A and N characters are typically used to encode postal code
Canadian postal code
A Canadian postal code is a six-character string that forms part of a postal address in Canada. Like British and Dutch postcodes, Canada's postal codes are alphanumeric. They are in the format A0A 0A0, where A is a letter and 0 is a digit, with a space separating the third and fourth characters...

s and country code
Country code
Country codes are short alphabetic or numeric geographical codes developed to represent countries and dependent areas, for use in data processing and communications. Several different systems have been developed to do this. The best known of these is ISO 3166-1...

s. Z characters are used for address locators, product types, and customer and service information. B characters are one bar each, and are used to encode base-4 machine IDs for Canada Post's internal uses.

The bars making up a character can be interpreted as base-3 digits. A full height bar encodes 0, a short lower bar (an ascender) encodes 1, and a short upper bar (a descender) encodes 2. The leftmost bar in a group is the most significant trit, and may have the value 3, with both upper and lower bars short (a tracker).

In other words, short upper and lower bars are assigned weights of 18 & 9, 6 & 3, and 2 & 1, from left to right. Since the first bar has 4 possible values, and the following bars have 3, 2 bars can encode 4×3 = 12 values, while 3 bars can encode 4×3×3 = 36.

N characters are simply encoded as the values 0–9. Only the value 9 requires a leading 3.

Z characters use the full 36 combinations representable by 3 bars. The values 0–25 encode the letters A–Z, and 26–35 encode the digits 0–9.

A characters have a somewhat peculiar encoding. They can also be decoded as three base-3 digits (a leading 3 is never used), with the values 2–26 mostly encoding A–Y. Exceptions are that 0 encodes M, 1 encodes H, 9 encodes Z (rather than H), and code 14 is not used (rather than encoding M).

PostBar formats

Canada Post uses nine different formats of PostBar codes—three "domestic" barcodes, used on mail within Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, two "global" codes, used to route mail outside Canada, three "service" codes, used on customer-applied barcodes, and an "internal" code, used for testing, maintenance, and tracking purposes by Canada Post.

Each barcode begins and ends with an identical pair of bars, known as "start" and "stop" fields. These are made up of one ascender and one tracker. The Data Content Identifier is always the first character after the start field.

Placeholders used to detail each PostBar format below are A, N, Z and B for the character sets described above, * for the start and stop fields, # for a space character (two full-height bars followed by one tracker), and [RS-nn] for the error-correction field, where nn is the number of bars used. Bold Z's indicate DCIs.

Domestic

See caution at bottom of article regarding use of PostBar codes.

DCI's used in domestic barcodes fall within the range of A–L.
  • PostBar.D07: * Z ANANAN [RS-12] *
  • PostBar.D12: * Z ANANAN ZZZZ # [RS-12] *
  • PostBar.D22: * Z ANANAN ZZZZZZZZZZZ [RS-12] *

Global

DCI's used in global barcodes fall within the range of 1–9.
  • PostBar.G12: * Z NNN ZZZZZZZZ [RS-12] *
  • PostBar.G22: * Z NNN ZZZZZZZZ ZZZZZZZZZZ [RS-12] *

Service

DCI's used in service barcodes fall within the range of M–U.
  • PostBar.S06: * Z ZZZZZ [RS-12] *
  • PostBar.S11: * Z ZZZZZZZZZZ [RS-12] *
  • PostBar.S21: * Z Z ZZZZZZZZZZZZZZZZZZZ [RS-12] *

Internal use

DCI's used in internal barcodes fall within the range of V–Z.
  • PostBar.C10: * Z ANANAN [RS-30] BBBB *

Caveat Emptor

The PostBar barcode dimensions, formats, and symbology examples in Canada Post's 4-State Bar Code Handbook and as actually implemented by Canada Post
Canada Post
Canada Post Corporation, known more simply as Canada Post , is the Canadian crown corporation which functions as the country's primary postal operator...

 are significantly different from the formats and symbology described in this article and in .

For PostBar format D12, as described in this article and shown here, the Postal Code
Postal code
A postal code is a series of letters and/or digits appended to a postal address for the purpose of sorting mail. Once postal codes were introduced, other applications became possible.In February 2005, 117 of the 190 member countries of the Universal Postal Union had postal code systems...

 is encoded using fifteen bars and the 'A' and 'N' character sets. The Address Locater encodes four alphanumerics using twelve bars and the 'Z' characters set. This format also includes a space character and twelve bars for Reed-Solomon error correction for a total count of forty nine bars.

On the other hand, PostBar format D52.01, as described in Canada Post's 4-State Bar Code Handbook and shown here, encodes the Postal Code using only twelve bars and an unknown symbology. It encodes nine alphanumerics in the Address Locater field using twenty one bars and another unknown symbology. It does not include any fields for space characters, but it does include twelve bars for Reed-Solomon error correction for a total count of fifty two bars.

Most significantly these two different formats use exactly the same code for their Data Content Identifier field; specifically two Full Height bars and an Ascender which corresponds to a 'B' character using the 'Z' symbology. From samples of mail being delivered by Canada Post
Canada Post
Canada Post Corporation, known more simply as Canada Post , is the Canadian crown corporation which functions as the country's primary postal operator...

, the D52.01 format with an unknown symbology is the implemented standard, and not format D12 as described in this article.

Postal customers who attempt to include a D12 formatted PostBar code, or any other PostBar format or symbology as described in this article may find it is misinterpreted by Canada Post's
Canada Post
Canada Post Corporation, known more simply as Canada Post , is the Canadian crown corporation which functions as the country's primary postal operator...

 sorting machinery. This could possibly delay or even prevent their mail being delivered.

See also

  • RM4SCC
    RM4SCC
    RM4SCC is the name of the barcode symbology used by the Royal Mail for its Cleanmail service. It enables UK postcodes as well as Delivery Point Suffixes to be easily read by a machine at high speed....

     – The barcode used by the British Royal Mail
  • Intelligent Mail barcode
    Intelligent Mail Barcode
    The Intelligent Mail Barcode is a 65-bar code for use on mail in the United States. The term “Intelligent Mail” refers to services offered by the United States Postal Service for domestic mail delivery. is intended to provide greater information and functionality than its predecessors POSTNET and...

     - The barcode used by the U.S. Postal Service
  • POSTNET
    POSTNET
    POSTNET is a barcode symbology that was used by the United States Postal Service to assist in directing mail. The ZIP Code or ZIP+4 code is encoded in half- and full-height bars...

    - The barcode used by the U.S. Postal Service until 2011
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK