The mysterious "X" at the end of the ID card number: the first 1 to the sixth place of the ID card number is the address code; 7 to 14 are the date of birth codes; Bits 15 to 17 are sequential codes; The bit 18 is the verification code. If the verification code is 10, it will be replaced by X..
A copy of the ID card should be endorsed by others: it is best to write the marks on the copy of the ID card with a blue or black pen; To indicate the purpose of the copy, you can generally write "This copy is only used for ×× use, and copying is invalid"; It is best to write the label in three lines, and draw a horizontal line at the end of each line to prevent others from adding other contents; It's best that the written mark is in contact with the actual content of the ID card, but don't suppress the key information.
Extended data:
Article 3 of the "Identity Card" Law The items registered in a resident's identity card include: name, gender, nationality, date of birth, address where the permanent residence is located, citizenship number, personal photo, fingerprint information, the validity period of the certificate and the issuing authority. Citizenship number is a unique and life-long identity code for every citizen, which is compiled by the public security organs according to the national standard of citizenship number.
Article 4 Resident identity cards shall be filled in with standardized Chinese characters and digital symbols conforming to national standards. The organs of self-government of ethnic autonomous areas may, according to the actual situation in their own areas, decide to use the characters of the ethnic groups exercising regional autonomy or choose a local common character for the contents registered in Chinese on their identity cards.
People's Network-The side with the national emblem is the front of the ID card.
Baidu encyclopedia-ID card method