Is north university of china a secret university? What do you mean by secret university?

It is a national second-class secret unit; North university of china, located in Taiyuan City, Shanxi Province, is a comprehensive teaching and research university founded by the Shanxi Provincial People's Government of People's Republic of China (PRC) and the National Bureau of Science, Technology and Industry for National Defense. As a key university in Shanxi Province, it was selected into the basic capacity building project of universities in the central and western regions of the country and the education and training plan for outstanding engineers of the Ministry of Education. It is a national second-class secret unit and is known as the "No.1 School of People's Ordnance Industry" in China.