Is the current classification system for library use still the Dewey Decimal System?

I wanted to visit a public library during my recent visit to Japan; hence, when we found one, we dropped in for a quick visit. In examining a few books, I noticed that Japanese books begin at the back and work toward the front. Modern books are printed left to right in rows on a page [due to the invention of the typewriter]; older books are printed in vertical columns. The front cover of books is the “back cover” in our system.

Then I noticed that books are cataloged with numbers from 000 to 999. This immediately triggered the possibility that the Dewey Decimal System was being used. I asked a reference librarian about this possibility. She did a two-minute internet search and confirmed my suspicion. In 1956, Japanese librarians modified the Dewey Decimal System used in US libraries since 1905. It became known as the Nippon Decimal Classification. Bingo! Another spinoff of the fact that the reconstruction of Japan following WWII was under the direction of the US Occupational Forces under General MacArthur.

In the USA, public libraries have used the Dewey Decimal System [DDS] since 1905. There are significant ambiguities in the DDS and a given book can be catalogued differently in various libraries. Hence, academic libraries have preferred to adopt the Library of Congress System because it allows every book to have the same call numbers everywhere that it is used.