There are three special areas in the Library that are distinguished by special location marks on the books: China, Japan, and Korea. The same classification system, RVK, that is used for the unified display of all other holdings in the Library is also used within each of these special areas. The reason for using location marks is that each of these regional-studies areas is in itself very heterogeneous so that books would have to be spread all over the library if they were integrated into the unified display.