Who determines what these guidelines are for each spell? The actual spell itself must have been discovered and recorded by someone - unless you just inherently know all of these spells, but that seems unlikely seeing as the book and movies series appear to be based on a school from what 'Google' has provided, and I doubt you would have need of a school if you already knew what would be taught - what I need to know is how that process takes place.
Hello Ron. My name is Loki. As I have said to Miss Lavender above, if you have heard of me, I would appreciate you not taking everything you have heard as fact.