@p @Terry @colonelj @sjw @colonelj @lanodan @mint @Moon 202 is more of "okay then, now go away". It's exactly as what happens in pleroma - we'll enqueue it for incoming federation, but there is no guarantee of causing any intended side-effects (may be dropped silently by MRF for example) and since entity is identical, no storage changes are expected.

409 per same spec is more of "hey, you tried to take the nickname that is already in use, fix that and retry right after". In case of APID conflict in server-to-server communication, there is nothing really server can change, and per RFC:

> This code is only allowed in situations where
> it is expected that the user might be able to resolve the conflict
> and resubmit the request