This term shows that poetry should indirectly and mildly advise a ruler against wrongdoing. The critic should resort mainly to tactful and sensitive wording, trying not to appear blunt or offensive when admonishing the ruler. The term first appeared in the “Introductions to Mao’s Version of The Book of Songs”; it was created by Confucian scholars in summarizing the various means of expression in The Book of Songs. Later, it became a criterion for measuring all works of art and literature. The core message is that, while poetry can be used to criticize or satirize a ruler and also to show discontent with social reality, a mild or indirect way should be employed, namely analogy, association, simile, and metaphor. This view is a manifestation of Confucian political ethics in the field of literary criticism.

Rulers use feng (ballads) to cultivate the people and the people use them to ridicule the rulers. So long as a critic advises the monarch mildly and through beautiful poetry, he will not be found guilty and the monarch he criticizes will become more careful in making decisions. These poems are called feng. (Introductions to Mao’s Version of The Book of Songs)