> Reddit also has a flag inside of their api called `nsfb`: Not Safe For Brand. They'll let you post it, and they'll host it, but they don't want most people to know that they'd host it, so they hide it from public, not-logged-in sections of the site.
I think you are confusing NSFB (brand_safe) with quarantining.
Quarantining is used for subs which are borderline being banned. Subs with frequent racism, subs with very fringe ideas (like 9/11 conspiracy theory). You need to login to view them, so they don't turn up in Google search etc. Example: https://www.reddit.com/r/911truth (try that link in a private browsing window if you are logged in to Reddit)
I don't think the brand_safe field is exposed in the public API any more (I presume it probably still exists behind the scenes). But my understanding of what it means, it is supposed to mark subs which are not advertiser-friendly. For example, subs that discuss controversial topics such as politics or religion. Anonymous users can view these subs fine and they turn up in Google. But, Reddit will display their own ads instead of third-party advertiser ads. Most companies don't want their advertising to pop up in the middle of a debate about whose religion is more correct, or what the Bible/Quran/etc has to say about sexual morality, it is bound to create a bad association in someone's mind.