宁七猫九
[níng qī māo jiŭ]
It appears to be a creative mix with little clear meaning in traditional Chinese culture or common understanding. '宁七' (níng qī) could suggest some kind of seven-day peace (宁静 - tranquility) while '猫九' (māo jiǔ) refers to nine cats. This combination might be purely personal and whimsical.