The term generally refers to different types of writings. Its meanings have evolved over time. During the Western and Eastern Han dynasties, it generally referred to writing techniques, writing styles, and various types of articles. During the Wei, Jin, and the Southern and Northern dynasties, literary scholars began to identify different features in different types of writings. They distinguished, for the first time, literary writings from those interpreting classical works, and identified pure literature as literary writings and practical writings as technical writings. They subsequently distinguished, on the basis of form, literary works such as poems, fu (赋 descriptive prose interspersed with verse), song (颂 essays of extolment), and zan (赞 essay of commendation) from essays such as memorials, documents, and policy proposals submitted to the emperor by officials. They concluded that all writings with rhyme were literary writings and those without were technical writings. Xiao Yi（508-554）, Emperor Yuan of Liang, argued further that literary writings should not only have rhyme, but also express the author’s inner feelings and use elaborate rhetoric, while technical writings required only general writing skills. Today, this term mainly refers to writing techniques and language styles.