Red travel codes represent cities in high-risk areas, and only give route reminders, which have nothing to do with health status.
Communication Big Data Travel Code is a free inquiry service provided by China ICT Institute in conjunction with China Telecom, China Mobile and China Unicom, using the signaling data of the mobile phone and through the location of the base station where the user's mobile phone is located. Mobile phone users can query all the city information they have visited in the previous 14 days through this service.
Red elimination method of travel code: the communication big data travel card prompts red, but its health code is still green. It doesn't matter, you can still travel normally, because the travel card is only marked with the city name of the high-risk area in red, which is only used as a travel reminder, regardless of the user's health status, and the previous information will be cleared after 14 days.