That’s the whole point here, allowing or disallowing phones should be the discretion of teachers based on what class they are actually teaching, be it language classes where there’s no need for phones or STEM classes where a pocket general purpose computer has many good uses and offer particularly good opportunities to teach students how to make constructive uses of smartphones in practical real life situations.

And instead having this being outright a ban on the school level, like being proposed here, is exactly the single worst possible way to do this. Having it banned on school level but having arbitrary “exception” being allowed defeated the whole purpose and makes it practically no difference from the above, and also open up lots of loopholes for abuse. You also can’t just have a list of school or government level “officially approved exceptions” because it’s ultimately about a technology, and technology is always evolving way faster than bureaucracy.