I recently learned about a handy tool for libraries that want to implement the optional arrangement of religions in the 200s. It was created by Mark Swenson, IT Manager for the Winnetka-Northfield Public Library District in Illinois. It's available at https://content.wnpld.org/deweyconvert.php.
The tool uses the number-building formulae that support the optional arrangement, since notably, most specific numbers in the arrangement still need to be built with reference to the standard numbers. Mark was kind enough to share some comments about the converter:
I was inspired to do this project after attending a presentation at PLA 2024 by Alex along with Elizabeth McKinstry and Matthew Jaquith of Springfield City Library and Emily McDonald of Lawrence Public Library. One of the resources which Emily provided was an Excel spreadsheet crosswalk for converting standard Dewey to the alternate arrangement and this is an implementation of that in code, first done in Perl for bulk conversion, and then in Dart/JavaScript for converting individual numbers. It was useful to us in converting our collection and I hope for it to be a useful resource for other libraries with the hope that there can be greater adoption of the alternate classification arrangement.
Thank you, Mark, for making this available!
This content was migrated from 025.431 The Dewey blog in September 2025.
