ITT we post everything we have and know about 4chan's moderation and how the site works in general.
I'll split the OP into several two or more posts, in each one dumping info and links.

Firt off, simple hidden pages:
>https://boards.4channel.org/test/
Hidden board. Can't be accessed and it's unknown how it looks like.
>https://boards.4channel.org/j/
Janny board. Can't be accessed right now but it was breached earlier. Stick around if you wanna see an archive of it from 2006 to 2014. Rumored to be inactive and used as a shitposting ground for jannies.
>https://a.4cdn.org/boards.json
A list of boards and their specifications, including cooldowns, bump limits, image limits and whether if webms can have audio.
>https://www.4chan.org/security
Don't do what this page tells you. All you get is your name put on a list that almost nobody will see since the page is hidden.
>https://www.4chan.org/sitemap.xml
I'm using this more as a post shorterner. This link has all the other hidden links that I didn't post here. Nothing special, just old contests and shit like that.

>Residential proxies/VPNs/etc
Free:
List of proxies detected by Wikipedia: https://en.wikipedia.org/wiki/Wikipedia:Open_proxy_detection (usually unbanned)
Mobile data: Your mobile data, if not rangebanned, works very well at ban evasion. To change your mobile IP, turn on airplane mode and then turn it off.
TuxlerVPN: https://www.tuxlervpn.com (works well, note that it's an unironic botnet)
Cheap:
MysteriumVPN: https://www.mysteriumvpn.com ($0.03/day, you can top up your account with crypto)
PacketStream: https://packetstream.io ($1.00/GB)
IPRoyal: https://iproyal.com ($0.80/GB, make sure to buy ONLY rotating residential proxies)

>Extensions
4tranx: https://www.4chan-x.net
4Chan Mass Reply: https://github.com/HamletDuFromage/4chan-mass-reply
Proxy switcher:
https://chrome.google.com/webstore/detail/proxy-switchyomega/padekgcemlokbadohgkifijomclgjgif (Chrome)
https://addons.mozilla.org/en-GB/firefox/addon/switchyomega/ (Firefox)

FAQ
>I'm still banned despite switching proxies
Clear your cookies. The 4chan_pass cookie is used to identify ban evaders.
>How does 4chan block so many IPs?
They use a paid API known as Blockscript (https://www.blocked.com). It blocks IPs considered to be abusive, such as IPs from datacenters, VPNs, Tor nodes, free proxies, etc.
>Why doesn't my post go through sometimes?
This depends on a variety of factors.
It could be your user-agent, or your file is secretly hashbanned, or the flood filter is on.
If 3 threads/replies are posted within a short period of time by users with different IPs and 4chan_pass cookies with a very little amount of posts attached to them (aka 'empty' 4chan_pass cookies), then the flood filter activates. It lasts exactly 5 minutes.
4chan compares your user-agent with what your TLS fingerprint says. e.g. If you have a Chrome TLS fingerprint, but your user-agent says you're using Firefox, this is an immediate redflag and your post doesn't go through. Use only user-agents that would fit your browser type.

post tor chans to solo-raid.

z5lcip4dafatwwa6hvyibizpzwycvwp67cjga3hzjhxhwvuyaqavxnid.onion/
nanochanqzaytwlydykbg5nxkgyjxk3zsrctxuoxdmbx5jbh2ydyprid.onion/
picochanwvqfa2xsrfzlul4x4aqtog2eljll5qnj5iagpbhx2vmfqnid.onion/

raid 4cringe with ancient 2016 memes

Well well, it seems like we've found the 'cord resposible for the BBC spam...
https://discord.com/channels/985633980583915650/985633981523427394

a lot of frogs on /bant/ right now

https://en.wikipedia.org/wiki/User:Tgeorgescu
I discovered a wikipedia editor who is soyjak personified. Some highlights from his page:
>Remember: truth is my weapon and if you misbehave, I will use it against you. If you want to accuse me of something nasty, present evidence or shut up forever. I have great respect for truth. At the same time I am a mastermind at weaponizing truth. I like wiki-persecuting bigots, pseudoscientists and quacks. Do you think I'm mean? The watchdog must bite.
>My religion: I believe in two Jewish prophets (Einstein and Spinoza). I recognize two Messiah: Vasily Arkhipov (vice admiral) and Stanislav Petrov.
>Hack tools used against my PC will be reported to Moscow. Swatting me will likely be regarded as (attempted) international terrorism. US citizens who try it will be lifted from their beds by the FBI.
I think this guy needs the ol' sharty treatment. He also posted his real name and credentials to his account, so it was easy to find a picture of him IRL and his official university webpage:
https://uva.academia.edu/TudorGeorgescu
https://uva.academia.edu/TudorGeorgescu/CurriculumVitae

What does the Sharty have against does?

YOU WILL RAID https://bstall.org

I'm definitely not just trying to advertise my site just like what frenschan is doing here in the guise of a raid.

(Honestly, if sharty ever closes down, I'd gladly make a soy board, and I'm also very lax on bans.)

69000000 boards.4chan.org/r9k/