Illegal. According to the "Urban Ethnic Work Regulations", business operations must not contain political or religious content, and must not infringe other people's reputation rights, trademark rights and other legitimate rights and interests. Hanging Hui signs is an infringement of the reputation rights of the Hui people and is illegal. The Hui nationality is an ethnic minority with a relatively large population in China, and is distributed in 31 provinces, autonomous regions, and municipalities directly under the Central Government.