> Accompanying it is a Victorian version of Google — books are arranged by a proprietary subject classification system designed by the organising supremo Charle

> Accompanying it is a Victorian version of Google — books are arranged by a proprietary subject classification system designed by the organising supremo Charles Hagberg Wright, librarian from 1893 to 1940. I had up until this point thought everyone just used the Dewey Decimal system, but it turns out library classification algorithms are quite a bit more nuanced than expected. > Some classification systems are more suitable for aiding subject access, rather than for shelf location. For example, Universal Decimal Classification, which uses a complicated notation of pluses and colons, is more difficult to use for the purpose of shelf arrangement but is more expressive compared to DDC in terms of showing relationships between subjects. Similarly faceted classification schemes are more difficult to use for shelf arrangement, unless the user has knowledge of the citation order. https://en.wikipedia.org/wiki/Library_classification https://en.wikipedia.org/wiki/Library_classification