I have started to use this system shortly after having first heard of it. I think the greatest challenge is that as I constantly create new things while only completing a fraction of them, I'd end up with a very “sparse” set of numbers being “active” in the end and unlike what is claimed by the system the relevance of directories for me is rarely linked to the time of their creation. Hence I needed to tweak this system a little to be useful to me and while it is a minor improvement over before I am still dissatisfied with the outcome...
An alternative organization system which is more lightweight and could also work well -- I am not affiliated, but would like to try to add some of these ideas to my own structuring approach: https://plaintext-productivity.net/3-02-file-folder-structur...
During the course of time the License of the JD system itself seems to have changed to a CC “NonCommercial” license. This really contradicts that this system is intended to be also useful in business contexts. I shall only look at my old copy where it is still under a DFGS-compliant license, but I wonder whether it is even possible to claim ownership on an organization system by means of a license? Wouldn't the only way to protect against it being used or described anywhere be a patent?