PHRASE
在…的旗帜下；为了…的事业（或信仰）
If someone does something under the banner of a particular cause, idea, or belief, they do it saying that they support that cause, idea, or belief.
例句
All countries march as one nation under the banner of friendship.
所有国家在友谊的旗帜下团结一致，共同前进。
Under the banner of education, we herd our children from ballet to basketball and back again.
打着教育的旗号，我们赶鸭子上架似的让孩子从芭蕾到篮球，不停地学这个学那个。