旗下

under the banner of

down / downwards / below / lower / later / next (week etc) / second (of two parts) / to decline / to go down / to arrive at (a decision, conclusion etc) / measure word to show the frequency of an action

flag / variant of 旗[qi2]

banner / flag / (in Qing times) Manchu (cf. 八旗[Ba1 qi2]) / administrative subdivision in inner Mongolia equivalent to 縣|县[xian4] county / CL:面[mian4]