Legal basis: According to the national standards of People's Republic of China (PRC)? According to GB11643-1999, the citizenship number is a characteristic combination code, which consists of 17 digit digital ontology code and digital check code. The order from left to right is: six-digit address code, eight-digit date of birth code, three-digit serial code and one-digit check code. People's Republic of China (PRC)? Resident identity card is an effective national legal certificate to prove the personal identity of citizens.