The index
We tend to think of our files — the stuff in your Documents folder — as ‘our system’. It’s how we think about our computers; it’s what we imagine when we think about a system like Johnny.Decimal.
Try to move away from this mindset.
Because there are now so many places that a thing can be. Files, yes. But also: email, your notes app, physical documents, an external hard drive or server, an online database, an app on your phone, an app in the cloud…
And so no wonder we can’t find anything any more. It used to be that we only had one place to look. Those days are over.
The index was designed to solve one problem, and as technology evolves it has grown to solve another.
First problem: re-use of IDs
The first problem is re-use of your Johnny.Decimal IDs.
Say you book a trip to Vietnam. It gets ID 16.24 Vietnam, 2023
. You have PDFs to save in your file system, and email confirmations to save in your email. No problem.
Then you book a quick trip to Melbourne. You don’t need to save a file, so you don’t create a folder in your file system. Your situation looks like this.
Now, you decide to go back to Southeast Asia. The first thing you need to save is a file. You look in your file system.
Tell me which number you use. And don’t pretend that you’ll remember that you’ve already used 16.25
in your email. You won’t.
How do I know? Because I did it myself.
You need an index as the central store of Johnny.Decimal IDs for your system. So now you don’t go to your file system to create a new ID: you go to your index.
Second problem: where is it?
Without an index, you have no way of knowing where all of your stuff is.
With an index, you just tell yourself.
16.25 Melbourne, 2025
---
Location: email
It’s that simple.
It’s an index, not an inventory
It’s worth noting that the purpose of this index is not to record the details of every item you save: it is only to record the IDs that you have assigned.
Your index needs to record this level of information:
10-19My area
11 My category
11.01My first ID
11.02My second ID
You don’t need to track what’s in each of your Johnny.Decimal folders:
10-19My area
11 My category
11.01My first ID
Document.doc
Picture.jpg
Spreadsheet.xls
11.02My second ID
How to keep your index
The simplest way to keep an index is in a notes app. I’ve tried other solutions, but they were all too ‘heavy’. Your system needs to be frictionless.
I use Bear but any app that allows you to quickly search your notes will work.
Simplenote is a good option for Windows or most other platforms.
There are two methods. I prefer the first.
1: One note per ID
To create a new Johnny.Decimal item, simply create a new note. Other than the title, which is the index entry, the note may be blank.
You must do this before you create a folder in your file system, or your email, or anywhere else. Creating the note is creating the new ID.
To create a new ID, search your notes for the relevant category. Your app should filter all notes to show only those that match. Identify the next available number and create a new note.
Example: Bear
Using Bear’s search to narrow our index to category 17
.
![Screenshot of the application 'Bear'. In the left pane the search term '17.' has been entered. The main pane shows those notes that match this criteria.](/img/_new/11.05.01-bear-filter-17.jpeg)
By including the .
in our search, we (usually) filter out other notes that just include the text ‘17’.
We can see that 17.04
is the next available number, so we create a note and then use that number wherever it is required.
![Bear again, and now we've created a new note using our next available ID, which is 17.04.](/img/_new/11.05.02-bear-17.04-new-note.png)
2: One file with all of your IDs
This style of index is more suitable when you might want to programatically query your system. It does work as a manual index but I found it more cumbersome.
Use one note — it’s always 00.00
in my system, which of course needs its own index entry — and record all of your numbers there.
![Bear again, this time with a single note at 00.00 which contains one line for each of our index entries.](/img/_new/11.05.03-bear-00.00-the-index.png)
I format mine as shown. Either use a fixed-width font in your notes app, or make it a ‘code block’.
In a future post I will expand on this index-as-single-file format.
Searching for items
When you’re saving all sorts of items in your system, you won’t always remember where they are. Did you save the workshop minutes in your email, or the shared file system?
You might look in the file system, not find anything, and think you didn’t save it. But you know you did!
The whole point of the Johnny.Decimal system is to remove this frustration.
Having a central index allows you to search for items by title, or filter your entire list by area or category. This lets you see, immediately, what you’ve saved.
If your system also tells you where that item is, then all the better. I record the location of each thing in its index note.
![You guessed it, Bear. This time we're showing one of our notes and in it we've written 'location: email' to indicate that this is where this item can be found.](/img/_new/11.05.04-bear-17.03-showing-location.png)
“This sounds like a lot of work…”
A lot of people see the index as an unnecessary burden. I encourage you to try it out: it takes less time than you think it will, and you’ll find ways that it will help you be even more organised.
I believe that the effort and time is worth it.
Non-note index techniques
Given how simple the index is, there are any number of ways you can implement yours.
Some of these are more relevant in shared scenarios. For example, if you collaborate on a project with colleagues.
Airtable (or any other database)
You can use any database system you like. Airtable1 is a great online database which I use for all sorts of things.
I’ve created a template database which you can use as a starter. You can copy it from here.
A spreadsheet
Obvious enough — and I don’t think it’s a great solution, to be honest — but you could always store your index in a spreadsheet.
At work: SharePoint lists
If you work for a large organisation, you may be able to ask your IT people to create you a list in SharePoint. This can work very well, and has the advantage of being visible to your entire team.
Anything else? Let me know
If you implemented your index another way, let me know and I’ll post it here.
Workshop
In the Workshop, we see Lucy creating her index using Apple Notes. Proving that you really can use even the most basic tools.
Footnotes
-
That link earns me a $10 referral credit if you sign up. If you’d rather not do that, that’s cool: just go to airtable.com. You can copy the template database either way. ↩