Afaik, that is not how "federation" works. It presents itself that way, so it is indeed tricky, but if you, from sh.itjust.works, having been invited to sh.itjust.works, want to post in a community on dubvee, then it is not the rules of sh.itjust.works that apply, but rather those of dubvee.

Damn that does sound unfriendly though - I can only hope that you got caught up incorrectly in a sweep, which I admit sounds rough but that is how the Beehaw & dubvee instances choose to work, and it is their choice to do however they please on their own machines, bought and paid for by them not us. Lemmy.ml similarly does as it pleases, as too does Hexbear.net, and lemmygrad.ml, and lemm.ee at least used to, and so on. It gets more difficult when piecing them together via federation though, especially when conflicts arise - e.g. between lemmy.world and lemmy.ml.

I have long been an advocate for a FAR greater level of transparency about such things than currently exists. Like lemmy.ml simply says "A community of privacy and FOSS enthusiasts, run by Lemmy’s developers" - as if that explains why they ban people from communities that they have never even so much as heard of, if they ever say anything remotely negative (or not positive enough?) about Russia, China, or North Korea? Beehaw, on the other hand, has an intricately detailed explanation of their policies - so them enacting such should not be a "surprise" to anyone posting or commenting in one of those communities.

However, the Lemmy software is set up to mostly ignore those kinds of messages (while PieFed does a fantastic job of placing them onto every single page - even an individual post has the community side-bar visible), so the burden falls to you to have to figure out all the myriad little fiefdoms and rules of what is or is not allowed on the various instances. Good luck! (or switch to PieFed I guess) But my point there is that it was not Admiral Patrick's fault for "having rules", though he did set himself up to fail by (like Beehaw) making rules that did not align with those used elsewhere in the Threadiverse.