What is the basis for the traffic police to approve the installation of warning lights and alarms?

When applying for police car registration, public security organs, state security organs, prisons, reeducation-through-labor administrative organs, people's courts and people's procuratorates shall fill in the approval form for police car number plates, submit legal certificates and vouchers, which shall be summarized by the municipal or equivalent competent department where the department is located, sent to the local public security organs at the same level for examination and approval, and then reported to the public security departments and bureaus of provinces, autonomous regions and municipalities directly under the Central Government for examination and approval.