Alternate project naming idea

I had to re-write this as I lost the original in the forum upgrade disaster.


The original JD implementation had no way of handling multiple projects. Fairly recently I came up with the PRO.AC.ID method, which assigns a 3-digit number as a project ID.

After using it for a while, I don’t think I like it. I don’t find the project IDs memorable and, worse, I find that the extra numbers make it harder for me to remember my category IDs.


It is worth noting that I think projects should be used sparingly. Before the idea existed, my entire life was a single ‘project’. I ran a 3-year Australia-wide data centre deployment as a single project.

You should aim to exhaust the basic AC.ID notation before you reach for multiple projects.

A previous idea

I had explored the idea of using letters rather than numbers before I documented the existing system. The idea was 3-letter abbreviations for project names. ‘Home’ becomes HME, the data centre project at work becomes DCP, and so on. I didn’t like this because it’s not memorable, it’s easy to get confused (did you choose HOM or HME?), and there’s no easy way to group projects.

The new idea

I suggest a new project ID format: a letter, followed by two numbers.

The letter serves as a grouping, and a mnemonic reminder: P for personal, W for work, whatever you like.

The numbers follow sequentially. Or not, if you prefer. It might be more memorable not to start at 01.

So now we have:

  • P01 for my first personal project.
  • Q01 for the first project at work, because the name of the company I work at starts with a ‘Q’.
    • Leaving the other letters available for when I change jobs.
  • If you’re a freelancer you might use C01 for the first client, and so on.

If you exhaust 100 projects within a letter, or all 26 letters, you’re doing it wrong.

What do you think?

Let me know! As soon as this occurred to me it seemed like the head-slappingly obvious solution. What am I missing?


I see some merit in this if you need that wider level of project-based split-out for your projects and files. The alpha suffix will keep things nicely separated and if the alpha has meaning, then it has served its purpose as an easier-to-remember structure. Let’s face it, you’re trying to be kind to your future self and make things easier to find.

As you indicated earlier, you ran a 3-year project on AC.ID alone, so it pays to think a while about what your actual needs are and live with the structures for a bit to see how they go.

I have some similarities to your suggested approach, as I use the project number more like an “entity” number and have folders that house both reference files and project numbers together. To explain, I am a self-employed IT consultant and have the following Project structure, albeit not with the alpha prefix that you’ve suggested.

My structure is:

100 - Personal
200 - My Company
3XX - Client projects and files.
301- Client 1
302 Client 2, etc

So, in Dropbox, For the project of putting my daughter’s CV together, I have 100 Personal\30-39 Career\30 Resumes\100.30.03 [Daughters name] to house my daughter’s resume and supporting documents. In my task management system (Notion) the project number/name was “100.30.03 Daughters resume” while we were putting this together.

I’m still wrestling with Projects and file storage numbering existing in the one structure, so I’ll give the approach you’ve indicated some thought. I sometimes have projects that have no supporting files and no folder in the system but still need to be identified within each area that they belong to as that’s easier for me to remember and find in my task manager. Likewise, I have reference files that have no active project relating to them.

But that’s the subject of another post! Thanks for putting this idea out there and for coming up with Johhny Decimal in the first place. As a former PARA user, I’m finding JD a solid foundation to base my storage and planning needs upon.

The journey continues!

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I have a question about running your three-year long project in just AC.ID format. Did you have other subfolders within your ID folder that did not have an ID? Because I find it very hard to wrap my head around the idea of managing materials from across many different areas of life with just two levels of organisation. For reference, this is my current JD setup but I’m finding it a bit unwieldy and am seriously considering moving to an AC.ID structure. But for example, I’m having trouble visualising how I would organise my modules.

I did cheat, and in such a specific way I can still remember the exact details 7 years later.

The project was ‘deploy data centres across Australia’. The issue I ran in to was when I needed to do the same thing at each location.

I had 72 Cabling & patching and within there 72.02 Structured cabling. This is a particular type of cabling that is installed in a data centre.

So far, so neat. I liked the simplicity of one number to capture that whole thing, and wanted anything to do with structured cabling in one folder in my email.

But then I ran in to the classic issue: I need another level of organisation. Because I want to distinguish between the data centres.

This would have been a solution, but I didn’t want to do it:

  • 72.02 Structured cabling (data centre 1)
  • 72.03 Structured cabling (data centre 2)
  • 72.12 Structured cabling (data centre x)

Instead, I created folders and an ad-hoc extension to the JD IDs:

  • 72.02.DC1
  • 72.02.DC2

And actually the DCs already came with their own 3-letter codes that I won’t share here, so I used those vs. ‘DC1’. This was pure luck and made them all super memorable.

This worked super well and is a strategy that I endorse. In this situation you have to break my system somehow: it’s a two-dimensional system, and we need to store three dimensions. So the question becomes how to do that the most gracefully.


At yes. Good to know this. And I kind of like the idea of doing a 2d system and then creating an ad hoc third dimension when necessary. I might adopt that.

Hey, Johnny! Thanks for all of the fantastic effort you’ve put in to introducing, maintaining, supporting, and sharing your system!

I noticed that you haven’t updated the main Johnny Decimal site with your new project system. Are you still feeling it out?

I ask because I’m struggling with introducing this concept into my system. I’m involved with four organizations, each with their own projects, one with many, many, many community projects that I’m personally involved with.

I’m using Obsidian as the backbone for my planning and then re-organizing my storage and Omnifocus areas afterwards.

I posted a bit about how I’m working here to help talk someone else through their planning for more detail, if you’re curious: Looking for assistance with my JD setup! - #5 by hfabulous

Anyway, I’m not trying to hijack your topic, just see where you landed!

Hi! Thanks for the kind words, I appreciate it.

So I’m in the middle of a full site re-write. The current site is maybe 4 years old and I’ve long forgotten how to update it! Haha. Kinda not really joking. The way it’s put together is really heavy. So I’m re-doing it from the ground up with the aim of having a lot more content on there, and having much more frequent updates. Weekly vs. 4-yearly. :smile:

I’m spending about 20 hours a week on it, basically as much as I can when I’m not at my ‘real job’. Taking days off (like today, a Monday) to work on it. So, watch this space! I’ll let you all know when there’s a sneak-peek ready.

I’d need a whole heap more information to be able to give a considered appraisal. Perhaps when I’ve got the site out of the way we can do a ‘consultation’ via Zoom – record it for YouTube? – and I can use your results as a case study? Anonymised to whatever extent you wish.

That’s exactly the sort of thing I can’t do with the current site, that the new site will enable. So in the mean time either drop us some more information here, or hang tight for a while.

No bother at all. Keep nagging me, I want to help I’ve just got a whole bunch going on.

I’d really appreciate taking you up on your generous offer, Johnny, thank you!

Systems like this are a big part of what I do to contribute to our not-for-profit game developer co-op. We have extensive meeting, Value Flow, and knowledge exchange setups. The community often asks me to bring perspectives into project, file, and other producer-related management tasks, so helping you share your fantastic work to the broader community would be an honor.

I’m in Toronto, so we have flipped-flopped schedules, but I’m certain we can find a point when you’re ready.

Cool! Let me think about scheduling — no need to wait for me to finish the site rebuild for this — and I’ll DM you.

Time won’t be an issue, I’m an early bird which is your mid-afternoon. Lots of opportunity to line up there.

Exciting! :partying_face:

Sounds great to me! Thanks, Johnny. I also think this is exciting!

Hey, Johnny, I notice that you use AC.ID.PRO here, which makes more sense to me personally. On your website, however, you call it PRO.AC.ID. Can you please explain this difference?

I hadn’t thought about it that way but I guess this example is a variation on the idea of a project.

The thing I need to think about – see above re: new site design and new content – is all of the various ways that you can go from the standard two-dimensional JD system (AC.ID) to some variety of a three-dimensional system.

There’s PRO.AC.ID, AC.ID.PRO, this thing here which isn’t really AC.ID.PRO it was AC.ID and then some extra digits for one particular task that touched multiple physical locations. They weren’t new projects, really.

And there are others. My plan is to trawl this forum for all of these posts, reconcile in to something sensible, and present the various options. I don’t think there’ll am certain that there will not be one-size-fits-all.

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Posting this here in case other people find it useful. I am currently trying a new AC.ID system with a slight twist.

My main problem was that I needed to track a number of research projects and courses that I teach, but the PRO.AC.ID format with letters seemed like overkill, particularly since I don’t have tons of personal projects that I need to track. I had been using a PRO.AC.ID system for a while, described here, but I was finding it too tedious to maintain and simply substituting the first number with letters seemed like it wouldn’t solve my problem.

So now what I’ve done is that I’m just using a two-level system with only my projects having an additional third level such as 21.02.W23. 21 is my projects category, 02 is the project ID, and W23 is Workpackage 2, task 3. I am going to come up with a similar three-level structure for my courses and try it out for a while.

Let’s see how it goes.

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