IDs go with files or folders or items?

Basically I’m trying to understand if IDs should point to a folder that serves as a container of related items or if IDs should point directly to an item/file. Then does that mean you’re limited to 99 files per category and if you need more than that the category is too broad?

10-19 Fitness and Health
├── 11 Nutrition
│       ├── 11.01 Meal Plan   --> Should this be a folder (with a single file inside) or file?
│       └── 11.02 Recipes     --> A folder with multiple [recipe].md files?
├── 12 Exercises
│       ├── 12.01 Deadlift    --> Same dilemma, what if I have a video demonstrating form and a personal 
│       └── 12.02 Overhead Press
│                  ├── Video Instruction.mp4
│                  ├── Video of my biggest OHP.mp4
│                  └── Personal
├── 13 Medication
└── 14 Running
        ├── 14.01 Favorite running shoes.png
        ├── 14.02 Coveted pair of running shoes.png
        ├── 14.03 Some thoughts on
        └── 14.04 List of all runs.rec

Is category 12 the right way to do it e.g. 12.02 or category 14 the correct way?

Thank you, I hope I’ve made my point of confusion clear enough.

And so far from all the methods of organizing a Second Brain and reducing cognitive load this one seems like it has the most bang for the buck imo.

99.9% of the time you want your IDs to be folders that then contain a bunch of files. Category 12, in your example.

Some of my folders do only include a single file. I usually don’t know this when I create it, it just turns out that way.

This thread also discusses this idea, and an exception. @Heloise has a category which is ‘sewing patterns’, and in this case one ID = one sewing pattern.

In this case she did not bother creating the folder, as she knew 100% that there would only ever be one file in it. This is definitely an edge case though, just for your information.