There were a few, not exaustive since it’s been a few months since I looked through the source code, some of this might have changed and there’s also a few other checks that I’m forgetting:

• 4chan screenshots (specifically anything that OCR identified as having “Anonymous #(number)” in it) were banned. Honestly this one is fine as a toggle but I think for a while it was just on by default in the code
• any community that had specific words in it were blocked at instance level. I think “meme” was there, a few swear words, and a few carryover reddit meme community names (196, I think nottheonion was also there, anything with “shitpost” in the name, etc.)
• There’s a hidden karma/social credit score based on a user’s interactions and net total karma hidden from them that gets impacted by any moderation actions, including some of the automated hardcoded ones (e.g. even trying to upload an image that gets flagged by the hardcoded checks)
• users with a low enough net score get shadow-banned without being informed