It is always important to remember that the National Electric Code isn't national. It is up to the states or other (more-local) AHJs to adopt it (or not). And

It is always important to remember that the National Electric Code isn't national. It is up to the states or other (more-local) AHJs to adopt it (or not). And many simply have not done so. For example: A person building a single-family home in Meigs County, Ohio, has no electrical code to follow, nor any electrical permits to pull, nor any government inspections of any electrical work. (Lacking code, there's no standard by which to permit nor to inspect the work.)