The problem is many people see every word in the books as a rule.
I don't see every word as a rule, but I do see every word as contributing to the interpretation of the rules. Frex, an example of play is not a rule, but contributes to our interpretation of the rules.
My view is that parts of the text should be grasped in differing ways. Flavour text for instance can help see what the rules are about, while not in itself being grasped as rules. Interpreters can suppose that the point of the rules is to achieve what is implied by the flavour text, and judge each rule according to that standard. When they have other flavour text in mind, they're more likely to change the rule. Or they may say that the rules stand for the game play, and read the flavour text as mostly blank.
Semantically, I think guidelines are loose rules that are expected to not always apply to every case to which they could apply, nor cover cases they apply to completely. They gesture in the direction of rules in potential. This is distinct from what others have said, when they take guidelines to be rules that can be lightly replaced.
Guidance text on the other hand is not rules, but advice on how to grasp and uphold the rules. Under this view, guidance text should never smuggle in new rules. Guidance text falls short of laws.
Laws I see generally in purpose as regulatory. Thus any laws in a game can be distinguished from its constitutive rules and guidelines.
So for me, the questions mooted by the thread title can be considered in terms beyond those of normative authority. Where one can bestow distinct semantic categories to rules vs laws vs guidelines. Although writing that now I can see that the way the title is structured, it really is the normative authority it is getting at.