The Dewey Decimal Classification (DDC), or Dewey Decimal System, is a proprietary library classification system first published in the United States by Melvil Dewey in 1876. It has been revised and expanded through 23 major editions, the latest issued in 2011, and has grown from a four-page pamphlet in 1876 with fewer than 1,000 classes to a four volume set.
Dewey Decimal Classification - Wikipedia https://en.wikipedia.org/wiki/Dewey_Decimal_Classification
That question was of some interest, because our son is the super at the reference library at the University of Texas in Austin.