In this section I will walk you through all of the core concepts in detail.

I strongly recommend that you read the core concepts section end-to-end, in the order shown below, at least once. This will give you a solid grasp of the system; you may then choose to use individual sections like a reference manual.

As you read it, you’ll have questions. Hold your horses and keep reading – I believe I have addressed most of them, but because this is a linear thing it might take me a few pages to get there.

The basic idea of Johnny.Decimal is very simple, but its power comes when you truly understand it. Reading this should give you that understanding; if you still have questions, or if I have not made something clear, please get in touch and I will help you.


You should be familiar with this section before you attempt to start your own Johnny.Decimal system.


You do not need to know everything in this section initially, but you will find it useful as you become more familiar with the system.