It´s a simple rule, stick to the rules! But you´d be surprised how many people try to break the rules. Maybe you´re one of those people that lives by the rules are meant to be broken motto, but in BDSM rules are there for a reason and not meant to be broken!
When a Dom/Domme doesn´t want to be touched then a sub shouldn´t try the patience of his or her Dom/Domme by trying to do it anyway. I know that not everyone is trying to be annoying, sometimes subs are just trying to be playful and provoke a Dom/Domme a bit hoping to be punished for that. But it´s a good idea to keep that to a minimum when you know that your Dom/Domme doesn´t like disobedience.
Not every Dom/Domme is that strict though, some might actually be more flexible. This isn´t a bad thing, but it might create some confusion because if you let one thing slide then what about the next thing and so on? Being strict with rules keeps it simple and keeping things simple is smart because that keeps things under control. I´d say as a Dom/Domme you want to keep things under control.
A lot of Doms/Dommes make rules, usually these rules are pretty standard but sometimes Dom/Dommes have some personal rules and as a sub you will have to stick to those rules. If you don´t want that then you´re probably not going to fit with that Dom/Domme and it´s better to move on. Because staying with someone that doesn´t fit well with you seems like a waste of time for you and for your Dom/Domme.
As a sub you can of course talk about the rules, I´d say giving your opinion is a good thing and maybe you can find a compromise when a sub isn´t a big fan of one or more rules. But remember that a Dom/Domme usually has these rules for a reason, so don´t expect any big changes. Rules keep a session fun and safe, both very important in BDSM!