This evening I’ve been reading through the documentation on the Johnny.Decimal system. It’s a method for organising documentation across multiple areas and categories and so falls within the realm of Personal knowledge management.

It’s not the only system of this type. I’ve looked at, and tried quite a few. As times and tools change, organisation structures change with them. Johnny.Decimal is a system that I will be investing time into.

Organising by numbered area and category seems easy enough to do1 but the secret sauce is in the index.

Here’s my problem. I have information in Obisidan, Zotero, Calibre/calibre-web, IMatch and to a lesser degree email.

The Index is multi-platform!

It should have been obvious. I could have done this with any system in the past — JD explicitly points it out. What does that mean? At the moment I’m reading Blackburn (1999) — Think which is a book about philosophy so let’s say the all things philosophy get coded under 23.12 - Philosophy2.

  • Calibre books on philosophy are tagged with 23.12.
  • Obsidian notes on philosophy go into the 23.12 folder.
  • Omnivore articles on on philosophy can be tagged 23.12
  • Podcasts on philosophy can be tagged 23.12
  • Research papers in Zotero are placed in a 23.12 category.
  • Passwords in 1Password for any philosophy related sites are tagged 23.12

And so on. This is extremely powerful for both filing and retrieval.

My mind is already racing with the possibilities. I’ve bought the workbook to help slow me down and think through it all. The recommendation is at least a week to play around with mapping things out.

After reading the material on the website I felt quite unwell and out of sorts. That happens when I’ve been perturbed. It’s a good thing.

There are a few things to work though. Obsidian folders are an obvious way to organise content, but within Obsidian I have an internal Quartz 4 structure for my website. Articles are moved to the sub-folder for publishing. So is it folders, or tags, or both? I may need to use projects but I don’t feel that’s right yet. I can see this Digital garden mapping to the same structure3 which will help me and my readers.


  1. Past experience tells me it won’t be and JD themself points this out in the excellent documentation.

  2. A purely arbitrary number.

  3. Rejigging the website isn’t a problem as Nothing is Sacred.