 The term "genres" refers to various aspects, such as to topic, theme, and subject matter, what similes or metaphors were considered appropriate or how they would be interpreted, and other considerations such as vocabulary and style.These genres were generally, but not always independent of the Classical Chinese poetry forms.Many or most of these forms and genres were developed by the Tang Dynasty, and the use and development of Classical Chinese poetry genres actively continued up until the May Fourth Movement, in 1919, and still continues even today in the 21st century.