Pronounced li zhu cut in "Tang Yun" and "Yun Hui", and long zhu cut in "Ji Yun", with the same pronunciation as the character "lou". "Shuowen Jiezi" explains it as Nan Yang Rang Xiang. Also pronounced luo hou cut in "Guang Yun" and lang hou cut in "Ji Yun", with the same pronunciation as the character "lou". The meaning is the same.