Evan Prodromou

I've added an [erratum](https://www.w3.org/wiki/ActivityPub_errata/Proposed) with this text: > In Section 6.3.1 "Partial updates", the following sentence should be deleted: A special exception is for when the value is the json...

Agreed on all this. I think we have another ticket open for "an objects", but this is more thorough. Also, a normative difference -- a tag can be any kind...

We have an erratum PR open for this issue: https://github.com/w3c/activitystreams/pull/626

Originated in discussions of #633

I've made a PR to add this erratum. We need group consensus to apply this erratum, so I will label "needs group input" and drop "needs erratum".

I think the two next steps for this process would be first documenting the different options that are actually used on the Fediverse today, as well as the suggested collection-management,...

I think this is also an issue with object ids, like `https://social.example/users/evanp/note/1`. I think we have a page about object identifiers at https://www.w3.org/wiki/ActivityPub/Primer/Object_identifiers, and it would be a good place...

@snarfed notes that we also need to note that if `preferredUsername` changes, remote systems need to update; they should not treat this as immutable just because it is on their...

The mutability and immutability of `preferredUsername` is also covered in the ActivityPub + WebFinger report, since it matters quite a bit for Webfinger.

> In the currently deployed ecosystem, this would probably be done by adding `attributedTo` to the Collection. I think this is the right way to do it.