General advice: you can usually be less specific than you think you need to be

When designing your system, you can probably be less specific than you think.

This post details the single area that managed most of my life for me for almost a decade. It worked just fine.

Remember, by the time you’re in to a category — 15 Technical, say — you’re already two levels deep in to a very organised hierarchy. That’s probably enough. Scanning that list for 15.34 List of server logins isn’t a burden.

What I’m saying is that you might not need to go so deep. In the first instance, try to avoid this:

10-19 Technical
   15 Remote login details
   15.01 List of server logins

…because you might find that there’s very little else in that category. Aim for categories that catch quite a lot of stuff, and if you find this isn’t working, break them out later.