The health code is black, indicating that the health code applied by the user is under review. After review, green code, yellow code and red code can be displayed.
Although the health code is only a two-dimensional code, it contains rich data information. In addition to containing the necessary personal basic information, there are authoritative data of relevant departments behind it. After background comparison and comprehensive judgment, these data form a "risk early warning" and are coded to provide the public with epidemic prevention-related information and health information. Coding rules shall be adjusted in time according to epidemic prevention and control requirements.