When your internet points on HN exceed some threshold you may be able to downvote. I’ve heard there’s also a thing called a supervote. (I have neither of these privileges)

This is not true, no matter how much karma you have, you can never downvote stories on HN, only flag.

Super down voting is something only mods can do (maintains the story, but it gets nuked off the site index)

You may be correct, though you have a lot fewer internet points than the person who was talking about downvoting ;)

Also, I was referring to a super upvote, not a downvote, sorry if this was unclear. I’m pretty sure this is a thing, I have it mentioned by an extremely high karma HNer.