I’m glad this works for some people, but it just never made sense to me.
Here’s their example:
And their example query about why one should use it:
“Hey Kristy, where can I find the payroll schedule?”
“Twelve dot oh-three.”Thanks, Kristy.
One shouldn’t have to ask Kristy where things are. What if Kristy is out that day?
Why not just name folders intuitively?
E.g.
Here’s my “not Johnny” example 
:
Where is the payroll schedule?
Well, that’s Finance (starts with F, sorted alphabetically, so that’s nice), and it’s Payroll, so there’s the Payroll folder, and, oh, there’s the Schedule for 2018 folder.
No codes to remember.
No need to duplicate category names like
“40-49 Sales/41 Sales figures”
“10-19 Finance/12 Payroll/12.03 Payroll schedule for 2018”
Not to mention all the superfluous numbers.
And no limitations to 00-99. If one suddenly needs 101 files, there’s no need to renumber the categories.