I don't understand how the green code became Huang Ma.

The reason why the green code becomes the yellow code is because the health code has moved and stayed near the key places where the confirmed cases and asymptomatic infected people have stayed, and may have had contact with the confirmed cases and asymptomatic infected people, so it is included in the scope of the yellow code. If two tests are completed within three days, that is, two nucleic acid tests are done, and the time interval between the two tests exceeds 72 hours, and the results are both negative, the system will remove the yellow code and turn it into a green code.

The reason why the green code becomes the yellow code is because the health code has moved and stayed near the key places where the confirmed cases and asymptomatic infected people have stayed, and may have had contact with the confirmed cases and asymptomatic infected people, so it is included in the scope of the yellow code. If two tests are completed within three days, that is, two nucleic acid tests are done, and the time interval between the two tests exceeds 72 hours, and the results are both negative, the system will remove the yellow code and turn it into a green code.

Health code:

The health code is based on the actual real data, which can be generated by citizens or people who have returned to work on their own online declaration and background audit. As an individual entering and leaving electronic certificate locally, the QR code can be declared once, which is universal in the whole city. The introduction of the health code aims to make the work of returning to work more accurate, scientific and orderly.