Hacker News Guidelines

The one thing I wish was added - either in the guidelines or as a change to the actual web UI - was replying to a comment that you're downvoting; it's frustrating both to have one's own comments downvoted without explanation, and to come across a comment that's grey without obvious reason (Was it factually incorrect? Endorsing an unpopular idea? It's not always obvious).

(I'm not saying HN should do exactly the same thing, but one example is Slashdot's system where a comment can get downvoted in a way that tags it specifically as trolling/offtopic/whatever - https://slashdot.org/faq/mod-metamod.shtml seems to describe it alright)

It's an interesting idea, but you'd end up with a situation where the worse the comment, the more discussion it generates due to the forced replies, which is sort of the opposite of what you want.