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Mansa Musa was the ruler of the Mali Empire in West Africa. Details recorded here should be sourced; unknown information is left blank.
MORE →Reflects the personal views, recollections, and perspective of the author, Mike Davis.
This is a personal recollection on the Move fire on May 13, 1985
RM4SCC (Royal Mail 4-State Customer Code)[1] is the name of the barcode character set based on the Royal Mail 4-State Bar Code symbology created by Royal Mail. The RM4SCC is used for the Royal Mail Cleanmail service. It enables UK postcodes 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.
PostNL uses a slightly modified version called KIX which stands for Klant index (Customer index); it differs from CBC in that it does not use the start and end symbols or the checksum, separates the house number and suffixes with an X, and is placed below the address.[2] Singapore Post uses RM4SCC without alteration.[3]
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.
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, giving a possible 44 = 256 combinations. For readability however, only a subset is included. There are 6 combinations of four bars that have two short and two long bars. With bars extending to the top and bars extending to the bottom, there are 6 x 6 = 36 possible combinations like this, with which the ten numerical symbols (0 to 9) and the 26 letters of the alphabet can be encoded. 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.[4] The DPS can be found in Royal Mail's Postcode Address File.
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 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.
| Top | Bottom (1=long bar, 0=short) | ||||||
|---|---|---|---|---|---|---|---|
| 0011 | 0101 | 0110 | 1001 | 1010 | 1100 | ||
| 1 | 2 | 3 | 4 | 5 | 6 | ||
| 0011 | 1 | 0 | 1 | 2 | 3 | 4 | 5 |
| 0101 | 2 | 6 | 7 | 8 | 9 | A | B |
| 0110 | 3 | C | D | E | F | G | H |
| 1001 | 4 | I | J | K | L | M | N |
| 1010 | 5 | O | P | Q | R | S | T |
| 1100 | 6 | U | V | W | X | Y | Z |
The check symbol is computed by summing the top and bottom half values separately, modulo 6, and combining the final sums to find the symbol.[4] 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 6,4,2,2,4,6,2,5, which sum to 31 = 6×5 + 1. The check symbol's bottom half value is 1, so it corresponds to the letter I.
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| Post office barcodes | ||
| 2D barcodes (stacked) | ||
| 2D barcodes (matrix) | ||
| Polar coordinate barcodes | ||
| Other | ||
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| Related topics | ||
Source: Wikipedia. Article content is retrieved live through the MediaWiki API.
RM4SCC (Royal Mail 4-State Customer Code) is the name of the barcode character set based on the Royal Mail 4-State Bar Code symbology created by Royal Mail. The RM4SCC is used for the Royal Mail Cleanmail service. It enables UK postcodes 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. PostNL uses a slightly modified version called KIX which stands for Klant index (Customer index); it differs from CBC in that it does not 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 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.
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 larger-than-letter-size pieces of mail, such as magazines) and parcels. This symbology, derived from the RM4SCC 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.
CleanMail may refer to: RM4SCC a barcode symbology used by the Royal Mail CleanMail Antispam an antispam filter software from Alinto, available in freeware and commercial editions.
A QR code, short for quick-response code, is a type of two-dimensional matrix barcode invented in 1994 by Masahiro Hara of the Japanese company Denso Wave for labelling automobile parts. It features white ("0") and black ("1") squares within a square grid featuring fiducial markers on the corners, readable by imaging devices like cameras, and processed using Reed–Solomon error correction until the image can be appropriately interpreted. The required data is then extracted from patterns that are present in both the horizontal and the vertical components of the QR image. Whereas a barcode is a machine-readable optical image that contains information specific to the labeled item, the QR code contains the data for a locator, an identifier, and web tracking. To store data efficiently, QR codes use four standardized modes of encoding: numeric, alphanumeric, byte or binary, and kanji. Compared to standard UPC barcodes, the QR labeling system was applied beyond the automobile industry because of faster reading of the optical image and greater data-storage capacity in applications such as product tracking, item identification, time tracking, document management, and general marketing. As of 2026, QR codes are used in a broad context, including both commercial tracking applications and convenience-oriented applications aimed at mobile phone users (termed mobile tagging). QR codes may be used to display text to the user, to open a webpage on the user's device, to add a vCard contact to the user's device, to open a Uniform Resource Identifier (URI), to connect to a wireless network, to compose an email or text message, or as a method of payment.
Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.
MORE →Brown v. Board of Education in 1954.
