According to the novel, a missing person notice was a radio program usually used to find missing people or people who had lost contact. Missing-person notices can be an important plot element in novels, helping readers understand the challenges and efforts of the protagonists and how they find missing people through the radio. In some novels, the missing person notice could even become a profession provided by the company or organization that the protagonist worked for. In this case, the protagonist will take on the task of finding the missing person and solve various problems together with other people. Of course, this was only one of the plot elements in the novel. In the real world, missing person notices were usually carried out by the police or civil organizations, and they had to abide by relevant laws and regulations.