I don't think it's possible to delete your own comment on HN. It's possible for the mods to "shadow delete" your comments: it still appears to you when you're

I don't think it's possible to delete your own comment on HN. It's possible for the mods to "shadow delete" your comments: it still appears to you when you're logged in, but no-one else can see it. (To see if any your comments have been shadow-deleted, check out the difference between news.ycombinator.com/threads?id=yourusername when you're logged in and logged out.)