While realizing the online endorsement of the residence permit, the "Police Uncle" APP also launched the three-color logo of the residence permit, which intuitively reminds the holder of the residence permit of the status of the certificate through the three colors of "red, yellow and green". "In the period of validity of the residence permit, it is displayed in green; If the residence permit enters the endorsement period, it will be displayed in yellow; If the use function of the residence permit is suspended, it will display red, "said the relevant person in charge of the Hangzhou Public Security Bureau. At the same time, they will use APP and SMS push services to remind the holders of residence permits to go through the endorsement procedures in time to avoid the suspension of the use of documents and affect the daily work and life of "new Hangzhou people".