I tend to restrict my downvotes for comments that don't add anything to the discussion. e.g. unhelpful comments (such as "Just google it!"), attempts at humour,

I tend to restrict my downvotes for comments that don't add anything to the discussion. e.g. unhelpful comments (such as "Just google it!"), attempts at humour, personal attacks etc. I don't know about "reddit-isms" per se, but I have seen the occasional "slashdot-isms". HN is neither Reddit nor Slashdot. Those forums still exist, and if that's your thing, go for it - over there.