Why did Wu Zetian give Wu Wen a white animal tattoo in The Secret History of Wu Zetian?

Wu Zetian gave clothes with animal patterns to officials of civil and military affairs, just to distinguish them from their ranks.

The animal patterns on the clothes of ancient officials can be traced back to the period of Wu Zetian. Before Wu Zetian, the categories and grades of officials were generally distinguished by the number of accessories and the color of clothes. Perhaps the more clothes and accessories an official has, the higher the rank of the official. In order to distinguish officials more conveniently, Wu Zetian came up with a way to embroider birds and animals on clothes. Weak civil servants, official clothes embroidered cranes and other birds; Military attaché s are braver, and official uniforms embroider fierce beasts. In this way, you can know whether an official is a civilian or a military commander by looking at his clothes. It is said that the term "devil wears Prada" originally refers to a minister who wears official clothes. At first, it was not a derogatory term, but a commendatory term, meaning a politician with high social status. If this person is called "the devil wears Prada", it is actually very enviable.

The design of the devil wears Prada used by Wu Zetian has been used by later generations, which has a great influence on later generations. However, in the middle and late Ming Dynasty, officials were corrupt, and the people complained bitterly, and they didn't have a good impression of the officials at that time. Therefore, "the devil wears prada" has gradually become a derogatory term and an abusive word.

To sum up, Wu Zetian's move is very innovative and practical for distinguishing officials, so it has been used in the future.