The only people who can answer your questions are the mods, so you should ask them. hn@ycombinator.com

https://en.wikipedia.org/wiki/Shadow_banning is common across social media platforms. HN has some automatic and some manual flagging. I reported some, both false positives and negatives. The "normal way to recover" is established users clicking the "vouch" button on flagged posts. I think the threshold is 500 karma, can't remember. I'm happy for every 'vouch'worthy item I discover. With 50 submissions per hour there's not enough users on the /new page to review everything and tastes are different.

Yes exactly HN silently filter domain. It has a strong anti-spam policy. Share and write comments in a genuine way. To check if your post is actually published check it from incognito browsing. To recover from a ghost penalty wait and write genuinely.

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