12345 the tip-off letter is written in three parts. Name, address and contact information. Complaint: seeking truth from facts, well-founded, not exaggerated or narrow-minded, with facts and evidence. Appeal: state clearly what you want to achieve through complaint. 12345 generally refers to the public service platform built by local people's governments, which consists of telephone 12345, mayor's mailbox, SMS, mobile phone client, Weibo, WeChat, etc. Hotline 12345 Improve the service level for the people, promote administration according to law, innovate social governance, and safeguard the legitimate rights and interests of natural persons, legal persons and other organizations.