__NOTOC__ RM4SCC (Royal Mail 4-State Customer Code is the name of the

barcode A barcode or bar code is a method of representing data in a visual, machine-readable form. Initially, barcodes represented data by varying the widths, spacings and sizes of parallel lines. These barcodes, now commonly referred to as linear or o ...

character set based on the Royal Mail 4-State Bar Code symbology created by

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. The RM4SCC is used for the Royal Mail Cleanmail service. It enables

UK postcodes Postal codes used in the United Kingdom, British Overseas Territories and Crown dependencies are known as postcodes (originally, postal codes). They are alphanumeric and were adopted nationally between 11 October 1959 and 1974, having been de ...

as well as Delivery Point Suffixes (DPSs) to be easily read by a machine at high speed. This barcode is known as CBC (Customer Bar Code) within Royal Mail.

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uses a slightly modified version called KIX which stands for Klant index (Customer index); it differs from CBC in that it doesn't use the start and end symbols or the checksum, separates the house number and suffixes with an X, and is placed below the address.

Singapore Post Singapore Post Limited (), commonly abbreviated as SingPost, is an associate company of Singtel and Singapore's designated Public Postal Licensee which provides domestic and international postal services. It also provides logistics services in ...

uses RM4SCC without alteration. There are strict guidelines governing usage of these barcodes, which allow for maximum readability by machines. They can be used with Royal Mail's Cleanmail system, as an alternative to OCR readable fonts, to allow businesses to easily and cheaply send large quantities of letters.

Encoding and content

An individual bar can be short, extend upwards, extend downwards, or extend both up and down. These four possibilities are reflected in the "four-state" name of the encoding. Each character is then made up of four of these bars. There are 36 possible combinations like this, and so 36 symbols: 0 to 9 and 26 letters. In addition, single-bar start and stop characters are defined. As the example shows, the complete barcode consists of a start character, the postcode, the Delivery Point Suffix (DPS), a checksum character, and a stop character. The DPS is a two-character code ranging from 1A to 9T, with codes 9U to 9Z being accepted as default codes when no DPS has been allocated. The DPS can be found in Royal Mail's Postcode Address File.

Checksum

For the purpose of calculating the checksum, the top and bottom halves of each character can be assigned the values shown in the table below. Each such value is derived by assigning weights of 4,2,1 and 0 to the extensions according to their position in the character, summing the weights, and taking

modulo In computing, the modulo operation returns the remainder or signed remainder of a division, after one number is divided by another (called the '' modulus'' of the operation). Given two positive numbers and , modulo (often abbreviated as ) is t ...

6 of the sum. For example the symbol for 'B' has bottom half extensions of its first two bars, represented below as 1100, the sum of their weights being 4+2+0+0 = 6, modulo 6 of which is 0. The check symbol is computed by summing the top and bottom half values separately,

6, and combining the final sums to find the symbol. In the example above, the top half values are 2,6,1,1,4,5,1,2. This sums to 22 = 6×3 + 4. Thus the check symbol has a top value of 4. The bottom half values are 6,4,2,2,4,0,2,5, which sum to 25 = 6×4 + 1. The check symbol's bottom half value is 1, so it corresponds to the letter I.

References

External links

Related websites * tp://ftp.royalmail.com/Downloads/public/ctf/rm/Cleanmail/Cleanmail_and_Cleanmail_Plus_brochure_05.pdf Royal Mail Cleanmail manual
tool + font
– calculates the checksum character for a postcode and produces its RM4SCC barcode.
check-digit explanation

{{Postal services in the United Kingdom Barcodes Postal system of the United Kingdom

Encoding and content

Checksum

See also

References

External links