Gregory's Server
@Gargron another one I just thought about is how Mastodon posts polls/questions, by having a "Question" activity as an object in a "Create" activity.
To my knowledge that's not in accordance to the spec (not fully against it either tbh) but my understanding of section 6.2.1 is that Create is needed only for creating "Objects", not activities. The former just get send to the inbox/outbox verbatim. (to me this seems more logical)