The noun, "rule" is an important word in any endeavor you attempt.
As you know if you read this blog on an irregular basis, I ask questions in the search engine slot, my search engine uses Google.
If you want to be a hairdresser your state, there are tests, the "rule" is an equivalent to the tests to determine your competence and usually passing the tests allows you to have a license. If you want to drive, you need to get a license.
Knowing the "rule" successfully achieves your goal.