European Article Number

EAN – is widespread standard of barcode that used for merchandise marking. GS1 organization is the registrant of EAN codes. The structure of EAN is free modifying, except a few common rules. Symbols must have square form and the light spaces between then from both sides. The code squares must have fixed height and are consist of modules. Dark bar and light space may consist between one to four modules. The symbols are placed on the merchandise exterior with possibility to scan these codes. First three numbers of the code are assigned by the International EAN registrant. First three digit contains information about product vendor region. The last digit is the control number.

Control number calculation algorithm. First step: remove the last digit from barcode. Step two: summarize the values of even digits. Step three: multiple the result by 3. Step fourth: summarize the values of odd digits. Step five: summarize the result of step fourth and three. Step six: subtract from 10 the outside right digit. Last digit is required for barcode confirmation.
Using of barcodes are not necessary.