Earlier quoted context omitted.
If the law is slow to change or there are no available pennies, the stores can adjust the prices to match the expected rounding of prices. I can't imagine someone being prosecuted from rounding a penny but it's a quick and easy way to avoid any doubt.
> the stores can adjust the prices to match the expected rounding of prices Not necessarily. Anything measured by weight will still be subject to this issue.
Of course we don't expect anyone to be charged fractional cents because our currency doesn't support it. So just changing our smallest currency unit from 1 cent to 5 cents.