The epigraph is the name of the word format. The forms of words are different from those of metrical poems: there are only four forms of metrical poems, but there are always more than one thousand forms of words (these forms are called word scores).
In order to be easy to remember and use, people give them some names, that is, epigrams. Sometimes, because it is several variants of the same format, several formats share the same epigram; Sometimes there are several aphorisms with the same format because each family has different names.
Extended data:
Some epigrams end with terms such as "order", "sound", "strength" and "slowness". "Ling" is related to the wine order, which is a kind of lyric ditty close to folk songs. Yin is a combination of aria and poetic style, and it is also the evolution of this kind of poetry.
"Slow" has the characteristics of long space, slow language rhythm and large rhyme spacing. "Jin" has the meaning of intimacy and simplicity, which may be no less related to tunes than Ling and Quotations, and refers to a melody that is longer than Ling but not as elegant and solemn as Slow Song.
Generally speaking, "Ling" belongs to "Xiaoling", "Yin" and "Jin" belong to "alto" and "slow" belongs to "long tune".