Bar codes are divided into four parts from left to right:
1-3 digits: * * 3 digits, corresponding to bar code 693, which is one of the national codes of China.
4-8 digits: **5 digits, corresponding to the barcode of 69838, representing the manufacturer's code, which is applied by the manufacturer and allocated by the state.
9- 12 digits: * * * 4 digits, corresponding to barcode 000 1, representing the commodity code in the factory, which is determined by the manufacturer.
13: * * *1,corresponding to 3 of the barcode, is a check code, which is calculated by the previous 12 bits according to a certain algorithm.
Extended data:
Almost every book has a concise mathematical model on the back. Even when people are reading excellent literary works, it seems that they can show mathematics through it.
Therefore, it is widely used in many fields, such as commodity circulation, book management, postal management, banking system and so on. Automatic bar code identification system consists of bar code label, bar code generating equipment, bar code reader and computer.
Baidu encyclopedia-barcode