Spark plug article

I was reading a spark plug article online. I have always use champion plug 12 heat range so never tried a hotter or colder plug. I found this interesting as different plug manufactures have different heat indexing.
Quote from article.
It is also important to note that Champion plugs use a larger number for a hotter plug while NGK plugs reference heat in the opposite direction, with hotter plugs using a lower number. So, it's important to know your spark plug manufacturer's reference numbers regarding heat range.

Just throwing this out there.