I arrived on this post after having posted about not knowing, necessarily, where my story should start. In general, the "rule" on that seems to be: it depends. Or, there is no rule. Or, it could derive from genre (see "It depends").
And that got me thinking, as one does, about just how many rules writers break. Regularly. Gleefully. A rule is a rule until it's in the way. A rule is a rule until the story needs it to....not be. And I'm not talking about lazy writing, or experimental writing (whatever that might mean); what I mean is good writers break rules.
Think about it.
Sentences must be long and descriptive and suchlike. And then you have Hemingway's bare, terse prose, which isn't really bare at all. The Main Character also frequently does not "win" in Hemingway, something I didn't consider as such until more recently, though that's more a "narrative" rule than a grammatical one.
Things like "ain't" are not acceptable, say. But then you have a dialect novel like The Adventures of Huckleberry Finn (I won't commit to assuming it's the "first" one, but it's got to be early, or perhaps one of the first American ones?)
People need to know what you're talking about. But then Tolkein came up with hobbits. It's in the "canon" now that The Hobbit went to a few publishers and was declined because nobody knew what a hobbit was. I don't know if it's true or not. I don't need to know if it's true; I just like the story, and I think that's important too.
The narrator of Rebecca never receives a name. Daphne DuMaurier did that on purpose, clearly.
House of Leaves (by Mark Z. Danielewski) and Pale Fire (by Vladmir Nabokov) are both fake stories about fake stories, with lots of footnotes and, in House of Leaves' case, a lot of different stuff going on with the text itself. Sixty years ago, would people turn a book around to read a page in a spiral? I dunno. I did it with House of Leaves (I've also seen both referred to as what could be considered "hypertext fiction" which is a thing I don't currently understand, necessarily [I do intellectually, anyway], but keep revisiting). Pale Fire's author isn't even "really" Nabokov, but listed in the book as John Shade, to further the layers.
Hell, even Moby Dick was shocking, in its direct attacks on God. I won't call Moby Dick popular (I'm pretty sure it wasn't), but it was different. Groundbreaking?
So you know what? Find out what works for you. Break rules. See if people notice. Or, if they notice, see if it upsets them or delights them. Both might actually be good. Both might be bad. It depends on you and your story.
And I think that, in a nutshell, might be the best rule: Use your best judgement.