As I recently wrote some thoughts about how replies work in the Fedidevs chat, I thought I’ll record them here. Maybe, this might end up as a document at one time. It might at least be a good starting point:
A replies section [of the ActivityPub specification] would be a great opportunity to explain how to crash email systems in the late 2000s? Admin sends an email to everybody. Bob replies using “Reply All” with a small comment. Claire, Dave, Emily, Frank, and so … use “Reply All” to tell Bob not to use “Reply All”. This enqueues enough messages for the mail server to die.
We should also clearly formulate the problem statements for various aspects of the protocol.
That might sound easy, but is not. Stating “specify how a reply should work” is simple. Formulating a good problem statement is hard. I would start by collecting complaints about reply synchronization, and stuff like that. Then there are “reply guys” and so on. People wanting “reply control”, and what not.
There is a reason FEP-5624: Per-object reply control policies has 69 answers and very little progress.
@aschrijver also has #30 - "Please untag me" - fediverse-ideas - Codeberg.org as an example for “reply behavior” one might want.
Maybe, some body feels to do some requirement gardening on that piece of fertile soil.