Trip codes come in four colors: red, orange, yellow and green.

Red: A trip code of red color represents a confirmed case of New Crown Pneumonia or a suspected case of New Crown Pneumonia.

Orange: A trip code of orange represents a close contact in the case of New Crown Pneumonia.

Yellow: A trip code of yellow means you've traveled to a medium-risk area.

Green: A trip code of green means that the environment is currently safe and you are not a suspected patient or close contact at New Crown Pneumonia.

Travel Code Principle:

Using cell phone signaling data, through the user's cell phone is located in the base station location to obtain information about the user's location. The big data of communication itinerary code, by the China Academy of Information and Communication Technology, China Telecom, China Mobile, China Unicom three basic telecom enterprises to use the cell phone signaling data, through the user's cell phone is located in the base station location to obtain, for the country's cell phone users free of charge to provide the query service, the cell phone users can be used through the service, query the first 14 days of my visit to all the cities and municipalities of the information.

In order to implement the differentiated prevention and control strategy of each province's zoning and grading classification and time-sharing, and to promote the resumption of work and production and the safe and orderly flow of personnel. The provinces in the medium and low risk areas with green code personnel, the province passes; high-risk areas with green code personnel, in accordance with the provisions of the local prevention and control command to travel, the rules of passage within the county by the county (city, district) prevention and control command to determine the rules of passage within the city by the municipal (state) prevention and control command to determine.