The CUCAT logo. A cat with the stars of the Southern Cross on it over the letters CUCAT.

Using Cataloguing Schemes in Computer File Systems


This page will describe the use of library cataloguing schemes in computer file systems as implemented by the Beyond Books, Beyond Barriers project of the Association for the Blind of Western Australia and the Curtin University Centre for Accessible Technology.

The problem

When I first started producing books for the project I would simply store each book in a directory named for the book's title itself. While this worked for a time it was rather like an old fashioned shelf list of libraries. It did not keep books together by subject. To do this I first started to subdivide the books by general subject. All scriptures went into a separate directory which was then divided further. While this worked it soon was the case that this too would become too complex to keep track of books in such a fashion. Further it relied on a judgement call for each book and that judgement might well vary from one person to another.

Traditional book libraries solve these problems by using cataloguing schemes. These schemes insure that books of a similar subject matter are shelved together. There are but a few of these systems in common use, they are:

Dewey Decimal System
The most common library cataloguing scheme in use world wide. Uses only arabic numbers. Has been translated into many languages.
Library of Congress
In use in academic libraries in the United States and Canada. Good for large collections of non-fiction books.
British Library system
Used by the British library which also employs the Dewey Decimal System.
Association for Computing Machinery (ACM) system
Used in the classification of computer science and related texts.

For the Beyond Books, Beyond Barriers project I settled on the Dewey Decimal System for the storage of the collection. This was done for several reasons:

  1. It is the most common of all the systems and is very well documented.
  2. Its use of numbers only permits extracting books of related content by means of computer programs using simple math and database techniques.
  3. It was the system in use by both the State Library of Western Australia and the Curtin University libraries.


Each book, which in the case of the Beyond Books, Beyond Barriers project could be several files ranging from DAISY file sets to MP3 to braille ready files, are collected into a single directory and that directory is giving the Dewey number corresponding to the book. For example consider the case of the title Botany Bay, True tales of early Australia a history of colonial Australia which would be stored in a directory named 994.0L364 this number breaks out as follows:

When we place the book's directory into the system we do so by following a path of nested directories to the correct location. In the case above that path is as follows from the books directory 900/990/994/994.0l364 this will result in all the books about Australian history being groups together in the 994 directory just as they would in a physical library.

In the event we have a book about the history of Western Australia the .0 would be replaced with the geographic number assigned to Western Australia which is 941 so a title dealing with Western Australia would be given the call number 994.941 followed by the cutter number.

This system insures that each book no matter how similar the title will have a unique location in the system and a directory name which is meaningful.

Using other schemes

Because modern computer operating systems are capable of having file pointers from one location to another, called symbolic links, it is possible to implement other schemes without having to store copies of the books in multiple locations.

In the case above the book could also be catalogued using the Library of Congress system under the following: PR9619.2.L26 Rather than create a copy we would simply link the existing 900/990/994/994.0l364 directory to PR/PR9619.2.L26 location.

Thus we now would have a single copy of the book held in two different schemes. In the case of the Beyond Books Beyond Barriers project our cataloguing database permit us to have both Dewey and Library of Congress numbers recorded for titles.


This simple system ensure that books or files of similar subject matter are collected together. It uses a well established and documented processes to do so. It can be quickly implemented with the zip files below and is nearly universal in it's application. This simple could be implemented with nearly any cataloguing scheme.


To help in implementing cataloguing file systems as described above I have created two .zip archives. These archives will expand into a set of nested directories as described. You can download them from the links below:

Greg Kearney, January 2009