I guess there are multiple pieces here.

First is the ActivityPub protocol. This can be compared to the Email protocol (there are actually multiple, but I’ll try to keep it simple). ActivityPub is not a website or a platform, but a way for servers to talk to each other to share social media type information. It seems fromthis wikipedia article that the standard is now published by W3C, who handle most of the commonly used standards for the web.

Then there is the site Mastodon. Mastodon is a twitter-like site, and it uses ActivityPub to allow one site to talk to another. Mastodon is open source, in which anyone with the necessary skills can contribute code. But the ultimate decider of what goes into the software is “Mastodon gGmbH”, a non-profit from Germany.

Then we have Lemmy, which is a reddit-like site that also uses the ActivityPub protocol to allow one site to talk to another. Lemmy is also open source, but unlike Mastodon there is not an organisation behind it, just a small group of core developers. But because it is open source, if something were to happen (changes people didn’t like, developers hit by bus, etc) then it is easy enough to copy the code and new developers can start working on it.

Then there’s the facebook platform apparently called "Threads. This is proprietary, no one knows the code and it’s not shared or open. Facebook have basically built their own independent platform, except for one little difference: it supports ActivityPub.

I’m really new to the Fediverse and this campaign, but if it doesn’t already exist then I wonder if what’s really needed is just a generally agreed code of conduct

The question is, who writes this code of conduct? It’s not really up to ActivityPub, they created a way for servers to talk, they aren’t involved in content at all.

Lemmy could create a code of conduct. They can’t force it on all Mastodon servers, because the code is open source so anyone can copy it and make their own service. But even if they could, what happens when a user from Mastodon starts commenting on a Lemmy post? If Mastodon isn’t following the code of conduct, do they have to try to somehow block all Mastodon servers? How would you even do this, when anyone can stand up a new server at any time, and make small or large changes to the code at any time?

Ok, so maybe that’s hard but it’s easier with Facebook, with their big central server model. Who writes the code of conduct that Facebook has to follow? How do you get approval from the 100+ different platforms using the ActivityPub protocol spread across over 40,000 different servers?

Does facebook get a say in the code of conduct? After all, they will let their users follow people on other servers and vice versa. If they do get a say, won’t they have massive sway? If they don’t then how is it any different from some servers blocking them and others not?

The problem with the fediverse is the same thing that makes it what it is: It’s open to anyone, and no one controls it.

Therefore I just don’t believe you could identify who should write a code of conduct, and even if you could, you’d have to persuade 40,000 servers to join in. This at it’s core is not much different from a petition to have servers block facebook.

If say Mastodon wrote a code of conduct, they might have the sway to get lots of servers to adopt it - but when facebook inevitably break it, they have very little power to do anything about it.

Sorry this is a bit of a rambly post, but the short answer is that I just don’t think there is a logical organisation to write a code of conduct, and even if there were, they would have no power of enforcement so you’d have to work that out first.