I’m new to this system, and I’m wondering how you can deal with deleting folders? If you delete them, wouldn’t that mess up the numbering system because there would be a gap?
I suppose you could say not to delete folders, but there might be situations when you do really want to delete a folder.
If you keep an index, it doesn’t matter.
Your file system is not your index!
Update: a corollary presents itself here.
If you do ever refer to files outside of your file system — in your email, in your notes app, whatever — then I say that you must have an independent index.
And if you do not ever refer to files outside of your file system, then who cares if you delete and re-use a number in your file system? There can be no negative consequence of doing so.
I would even go one step further and say: If you don’t reference your file system externally, you might as well do without numbers altogether and just adopt J.D’s core principles.