[Houshalter]

Someone once did an analysis on HN posts and their ranking relative to the time they were posted and votes. And they found posts with certain keywords were heavily penalized and sort of soft banned from the site. IIRC it included stuff like "NSA" and "HN" and posts from certain sites like reddit and youtube (but I could be remembering.)

Having the full list of banned keywords, or even acknowledging there is a list, could cause drama. And it's easily evaded if people know about it, like when reddit banned "Tesla" posts got through by misspelling it "Telsa".

There's also other stuff like a controversy filter, that detects articles with more comments than votes and penalizes them. I try to avoid commenting in articles that are getting close to the limit to avoid triggering it.