The Johnny Decimal System (JDS) is a method for organizing information in a logical and easy-to-navigate way, inspired by the Dewey Decimal System used in libraries. It assigns numerical codes to categories and subcategories to keep files, documents, and tasks systematically grouped.
I first discovered the JDS about two years ago as I was building a digital library of books and other publications for my personal use. I remembered the Dewy Decimal system used in the libraries of my youth and thought there had to be an equivalent. In a short search I discovered the JDS and I have used it both personally and professionally ever since.
My Professional File Structure
My current employer used Microsoft Windows and 365 primarily and therefore I live in the Windows space professionally. As a Linux user in a personal setting, I have discovered key differences between the operating systems which I believe must be noted.
- Case Sensitivity: Linux is case sensitive, Windows is not. Therefore a directory named `my folder` will be interpreted differently on both systems. This is important if you may expect to share files with someone else using a different OS.
- Space Handling: Windows will allow spaces in filenames and subsequently make up the difference when searching or pointing a URL to the file. Linux on the other hand is very specific about spaces in file names and will require a little more care in naming. I use “.” to space my files names in Linux and that does not translate well as Windows sees the characters after the last period of a file name to be a file extension. Windows also sees periods (before the extension) as part of the words and does not stop when processing the name.
With that said, below is a top-level snapshot of how I structure my folders in a professional setting.
| Section | Name | Full Name |
| 00-09 | general | 00-09-general |
| 10-19 | staff | 10-19-staff |
| 20-29 | documentation | 20-29-documentation |
| 30-39 | managerial | 30-39-managerial |
| 40-49 | finance | 40-49-finance |
| 50-59 | personal | 50-59-personal |
| 60-69 | corporate | 60-69-corporate |
| 70-79 | projects | 70-79-projects |
| 80-89 | systems | 80-89-systems |
| 90-99 | archives | 90-99-archives |
Within each top level folder there are aptly named sub-folders. Let’s use 10-19-staff for example.
| 10-19 | staff | 10-19-staff |
| 11 | direct-reports | |
| 12 | mentees | |
| 13 | candidates | |
| 14 | reports | |
| 15 | forms |
Within folder 11 I would have sub-folders named as such 11-01-direct_report_name. This allows me to have an infinite number of folders as needed.
Quick Access and Recall
By using this system I can quickly navigate to the directory or files I need simply because I know the top-level folder and its category. If I am looking for an invoice I know to start with 40-49-finance. From there I can quickly find my invoices folder. It is important to maintain a uniform filename structure or else you could be searching aimlessly. Keeping with the example, creating a folder for each vendor (ex. 41-acme_supply) is helpful and then name each invoice with the following format, acme_supply-2024_05_17. By using the vendor name in the file name you will be able to easily identify it in a search.
| 40-49 | finance | 40-49-finance |
| 41 | invoices | |
| 42 | quotes | |
| 43 | purchase-requests | |
| 44 | licenses |
Transitioning to JDS
If you want to try using the JDS I suggest start by creating a new set of folders within your home directory and moving your existing files into them as you see fit. This was a challenge for me in the beginning as I had files I have never really thought to categorize before. It took some time and thought but I got there and I still continue to transition some things when I clean up my files.
Conclusion
This system is straightforward and so very helpful as a personal system. While I am sure something could be employed in a large organization, getting everyone on-board could prove challenging. The JDS is perfect for me and I encourage you to try it out for yourself.