The book stand is used to support books to stand smoothly. Many materials such as iron and stainless steel are made into "L" shape and appear in pairs. The book stand can prevent a row of standing books from tilting and tilting to prevent the books from being bent, bent or damaged. Book stands can also be used to summarize and organize different types of books. Most libraries use book stands to arrange gapped book shelves. Companies and individuals can also use book stands to create neat book materials on a flat desk. In the concept of stamp duty, the term "book" refers to various contracts, papers, books, etc. that are generated in written form, and refers to the behavior of signing contracts and agreements.