Dewey Decimal Classification

The Dewey Decimal Classification (DDC), or Dewey Decimal System, is a proprietary library classification system created by Melvil Dewey in 1876. It has been revised and expanded through 23 major editions, the latest issued in 2011. Dewey was responsible for all revisions until his death in 1931. A designation number, such as Dewey 16 for the 16th edition, is given for each revision.