Consumers are familiar with the consistent black and white barcode stripes on product packaging. But not everyone knows what information is hidden under it, what a barcode can tell about.
The most common barcode is the European Article Numbering EAN-13. In the USA and Canada, the 12-bit UPC code is used.
The first three characters in the digital value of the barcode are the code of the regional representation of the association (prefix of the national organization) in which the manufacturer of the product is registered. Most of the enterprises prefer to register in the representative office of the associations of their countries, but the association does not prohibit the registration of the enterprise in another country, therefore, the country of production of the goods cannot be determined by the first three digits.
Codes starting with two (prefixes 200 to 299) are reserved separately. These codes are used by businesses for their own purposes, usually retail, and indicate price, weight, and other parameters. They are not used outside the enterprise and are not registered or regulated by third parties.
The next 4-6 digits are the manufacturer's code (registration number of the manufacturer of the product). Each regional prefix is allocated for registration from ten thousand enterprises to a million. The length of this field depends on the regulations of the regional office. With a larger field size, more businesses can be registered, but then each business is allowed to register a smaller quantity of goods (next numbers). Thus, if the company code is 6 digits, then each company is given the opportunity to register 1000 product units.
The code of the product itself is the next 3-5 digits. The length of this segment depends on how the length of the enterprise code was chosen by the registrar as the base one. At the same time, the digital code of the product does not carry any semantic factor. The Association recommends the consistent assignment of codes to goods, as new types of products are released without putting any specific semantic load into this code. This is just the serial number of the product item, which the terminal computer in the store simply takes from its own computer base, where the name and price of the product is stored.
The last digit is the check number and is used to verify that the scanner reads the strokes correctly. The numbers in even places are added and multiplied by 3. Next, the numbers in odd places are added. Then the results are summed up and only the figure in the last place is left in the final amount. Then this figure is subtracted from 10. The resulting difference is the check number, which must match the one indicated by the last in the barcode.
