Earlier quoted context omitted.
> Suggestions welcome "This domain is not allowed on HN" as an error message upon submission.
That’s not going to work, because now that’s an API for spammers to bulk process against a domain list. The only available API must be human communication to the mod team, or the spammers will overcome it with automation.
It's quite possible the reason the list isn't public is because it would give away information about what thought is allowed and what thought isn't.