Literature can be divided into first-class literature, second-class literature and third-class literature according to its content, nature and processing mode. Primary literature refers to the original literature created on the basis of the author's own research results, such as periodical papers, research reports, patent specifications, conference papers, etc. Secondary literature is a kind of literature produced by processing primary literature, such as bibliography, title record, introduction, abstract and other retrieval tools. The three documents are based on the first-level documents and the second-level documents. People usually refer to these documents as the results of "information research", such as reviews, thematic reviews, annual summaries of disciplines, progress reports, data manuals and so on. Similarly, some people divide intelligence into primary intelligence, secondary intelligence and tertiary intelligence.
Details, Baidu Encyclopedia: a document.
According to this situation, if the poem is a manuscript, it is a document.