HN does not support post down-voting. You can however down-vote comments - as long as they are not replies to a comment of your own. Even then, the number of do

HN does not support post down-voting. You can however down-vote comments - as long as they are not replies to a comment of your own. Even then, the number of down votes is limited. With a certain Karma threshold (the value changes over time) you can flag inappropriate posts and comments for moderation and I understand that a certain number of such flags set before a post reaches a minimum up-vote value will cause that post to be deleted. Personally I see no need for down voting.