According to Cambridge Dictionary, a rule is
an accepted principle or instruction that states the way things are or should be done, and tells you what you are allowed or are not allowed to do
We cannot use all the determiners with all types of noun. We can use some determiners with any type of noun, but others must be followed by certain types of noun.
There are two sentences above, is it reasonable to say the following?
The tutorial starts with two rules about the usage of determiners.
In other words, what is A rule when talking about grammar? Is each complete sentence a rule?
Is an exception in grammar a rule?