Is it illegal for institutions not to make up?

Not illegal. It is not illegal for public institutions not to make up. For example, the recruitment announcement stipulates that all aspects of recruitment are not supplemented, which is ok. It is impossible to judge whether it is reasonable or not and whether it complies with laws and regulations. Institutions refer to social service organizations organized by state organs or other organizations with the purpose of social welfare and engaged in education, science and technology, culture, health and other activities. Institutions accept the leadership of the government and are legal entities in the form of organizations or institutions.