Bit 7~ 14: birth date code, indicating the date of birth of the coded object, which is implemented according to GB/T7408, and there is no separator between the date of birth codes;
15~ 17 digits: serial number, indicating the serial number compiled for people born in the same year, the same month and the same day in the area identified by the same address code. Odd numbers of serial codes are assigned to men and even numbers to women.
18 bit: check code, which is calculated according to the first 17 bit and the check code of ISO 7064: 1983. MOD 1 1-2。
Extended data:
Supplementary explanation of ID number
Address code: compared with the first-generation ID card, the address code of the second-generation ID card has not changed, and the first six digits are still address codes, which are consistent with the administrative division code issued by the Ministry of Civil Affairs;
Date of birth code: the second-generation ID card is changed from 6 digits to 8 digits, and the 7th digit to14th digit is the date of birth code, in which the year is represented by 4 digits. For example, a person born in March of 1987 has a date of birth code of XXXXXX19870313xxx;
Sequence code: 15 to 17 are sequence codes, which are used to distinguish people born in the same year, month and day, and the specific numbers used for centenarians in the sequence code are cancelled;
Check code: bit 18 is the check code, which is mainly used to check whether the first 17 bits of the citizen ID number input by the computer are correct. Its value range is 0 to 10. When the value is equal to 10, it is represented by the Roman numeral symbol X. ..
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