[mtmail]

Check https://news.ycombinator.com/showhn.html and note the link on 'tips' in the text (hard to see). Have a look at popular past https://news.ycombinator.com/show submissions (e.g. anything over 100 points) and the text (first comment) they wrote.

Afaik the prefix "Launch HN" is reserved for YCombinator companies https://news.ycombinator.com/launches