On HN a post only counts as a dupe if it got significant attention, which that one didn't (only 3 points and 2 comments - but we'll merge the comments hither)

When an article hasn't had significant attention yet, we let reposts through (after 8 hours) - this is on purpose, to give good articles multiple chances at getting attention.

Of course that leaves the submitters in a bit of a lottery situation, but it at least evens out in the long run if you keep submitting good articles!

Nope - we just figured out one day that tutorials aren't intellectually interesting, in one of those obvious-once-you-see-it moments.

Edit: here's an explanation about this that I send to people who email "why was my thing downranked" when $thing was a tutorial:

Tutorials are not a great fit for HN. HN readers are looking for stories of intellectual interest that go deeply into a topic. Tutorials are great for readers who need to do the specific task the tutorial is about, but that is a small percentage of the total audience. Also, they tend to be directed toward beginners, which is wonderful, but not what the HN audience is looking for. Such articles rarely do well as HN submissions. You'd be better off writing something of general interest for an audience of smart hackers.

Email us at hn@ycombinator.com if you want some tips about how to present this to HN. (Same invitation goes for everybody who wants such tips.)

Edit: here's what I sent the users who emailed:

If you're sharing your own work and there's a way to try it out, put "Show HN" in the title. Make sure you've read the Show HN guidelines: https://news.ycombinator.com/showhn.html.

Include text giving the backstory of how you came to work on this, and explaining what's different about it. That tends to seed discussion in a good direction. (Your text should show up at the top of the Show HN submission, but if for some reason it doesn't, add it as a first comment to the thread. Either way is fine.)

Include a clear statement of what your project is or does. If you don't, the discussion will consist of "I can't tell what this is".

Include links to any previous HN threads that are relevant. Readers like those.

Drop any language that sounds like marketing or sales. On HN, that is an instant turnoff. Use factual, direct language. Personal stories and technical details are great.

For Show HN, the product/project needs to actually exist and there needs to be a way for people to try it out. It can't just be a landing page or market test or fundraiser or a blog post or a curated list or other reading material. Please respect this rule. If we allowed "Show HN" on all those things, nearly every post would be a Show HN.

Please make it easy for users to try your thing out, preferably without having to sign up, get a confirmation email, and other such barriers. You'll get more feedback that way, plus HN users get ornery if you make them jump through hoops.

If it's hardware or something that's not so easy to try out over the internet, find a different way to show how it actually works—a video, for example, or a detailed post with photos.

Don't have your username be that of your company or project. It creates a feeling of using HN for promotion and of not really participating as a person. You don't have to use your real name, just something to indicate that you're here as a human, not a brand. If you'd like to change your username, email hn@ycombinator.com.

If you're comfortable doing so, put your email address in your profile so we can contact you if we notice anything, and also so we can send you a repost invite. We do that sometimes.

Make sure your friends and users do not add booster comments in the thread. HN users are adept at picking up on those, they consider it spamming, and they will flame you for it. If a friend or a fan has something interesting to say, that's fine, but comments should not be promotional.

You can post a new release as a Show HN only if the new version is significantly different. It shouldn't just be an incremental upgrade. If you do repost, add a comment linking to the previous Show HN and explaining what is different from last time. This should probably only happen once or twice a year—more starts to be excessive.