The descriptive characteristics of books include: the person in charge, the publishing house, the title, the date of publication, the edition, the place of publication, the content summary, the book number, the key words and so on.

The characteristics of periodical description are: article title, publication name, publication year, issue number, person in charge, abstract, etc.

The description features of patent documents include: patent number, patent name, patent authorization institution, patentee, etc.