I’ve just released a new version of the Free Decimal Correspondence (FDC). FDC is a set of associations between numbers and subject terms that can be used as the basis for linear shelving or subject browsing of a simple library collection or repository. Like the earlier releases, it’s intended to be reasonably compatible with existing library standards; in particular, with OCLC’s Dewey Decimal Classification (DDC) and the Library of Congress Subject Headings (LCSH). (Keep in mind, though, that both of those standards go into considerably more detail than FDC does; and neither OCLC nor the Library of Congress sponsors or endorses the FDC in any way.) This version of the FDC, like the previous releases, is dedicated to the public domain. More information about the FDC can be found here.
There are two noteworthy features of this release. First of all, I’ve now defined corresponding subjects for every whole number (from 000 to 999) that’s also defined (and non-optional) in the DDC. In addition, I’ve gone past the decimal point in some cases to include additional subjects that may be useful in some collections and repositories. This means that the FDC should now cover at least as many subjects as OCLC’s Dewey Decimal Classification summaries, the most detailed official free-to-read summary of the present-day DDC I know about.
In addition, I’ve now using Creative Commons‘ new CC0 dedication to dedicate the FDC to the public domain. I’m hoping this will provide more authoritative legalese for clarifying the public domain status of FDC, and also raise awareness of CC0.
OCLC claims copyright and trademark on the DDC, and while the summary of DDC can be freely read on the Web, its use appears to be governed by this license, which states, among other things, that users may “not copy, reproduce, alter, modify, create derivative works, or publicly display any content (except for your own non-commercial use)”. It further clarifies that “‘non-commercial use’ … is not to be construed as permitting use of the DDC that (although internal) supports or otherwise facilitates your commercial activities.” (Note also that the linked license applies only to the DDC summary, not to the complete DDC. If you want a license for the full DDC, you’ll need to contact OCLC.)
With FDC, as with all CC0 and other public domain works, none of the restrictions above apply. Do with it what you like.
This new release is version 0.05. As the number suggests, this is still essentially a working draft. My first draft was released a few months ago on Public Domain Day. I intend my work on FDC to be a lightweight, spare time project, and therefore hope to advance to a “1.0” release soon, and leave further development, if desired, to others.
Between now and then, I’m not planning to make FDC much bigger than it is now. But there are still various other subjects not defined at the unit level that are common in repositories and small library collections, and that might be useful to add. (I originally started this after someone said they wanted to have a Dewey-like classification system for their repository, without worrying about licensing issues.) I’m happy to take suggestions of additional subjects to include in the next release. (But use your own subjects of interest, and not terms taken from an OCLC publication.) I’d also be very interested in hearing about (and fixing) mistakes, inconsistencies, redundancies, and correspondences that could be made more compatible with current library practice than what I have now.
There are numerous classification schemes you can use for collections. My page about FDC includes some discussion of the better-known alternatives you might want to consider. And if you’d like to work on a new scheme without worrying about compatibility with other systems, you might be interested in the Open Shelves Classification, an ongoing project sponsored by Tim Spalding of LibraryThing.
If FDC sounds like something you’d like to use, adapt, or experiment with, go right ahead. There’s no need to wait for any further releases, or to ask me about what you want to do, unless you’d like to. Have at it, and have fun!