One comment stands out to me:
> Whether to add it to the formal guidelines (https://news.ycombinator.com/newsguidelines.html) is a different question, of course. I'm reluctant to do that, partly because it arguably follows from what's there, partly because this is still a pretty fuzzy area that is rapidly evolving, and partly because the community is already handling this issue pretty well.
I guess me raising this question is because it feels maybe slightly off that people can't really know about this unwritten rule until they break it or see someone else break it and people tell them why. It is true that the community seems to handle it with downvotes, but it might not be clear enough why something gets downvoted, people can't see the intent. And it also seems like an inefficient way of communicating community norms, by telling users about them once they've broken them.
Being upfront with what rules and norms to follow, like the guidelines already do for most things, feels more honest and welcoming for others to join in on discussions.