Back before searching for files was built into the file explorer in Windows, I created a folder scheme where each directory had 10 subfolders named 0-9. You needed the “pin” to find the right one. It was good for maybe 4 deep? before it the folder creation script fell apart.

Disclaimer: this was so long ago, and this post triggered the memory, so I honestly can’t remember if this was just an idea I had that didn’t work, or if it was a real thing I managed to pull off with some basic batch scripting. Either way though, the folder decoy thing was real.