From the W3C spec: all objects distributed by the ActivityPub protocol MUST have unique global identifiers (...) must fall into one of the following groups:
- Publicly dereferencable URIs, such as HTTPS URIs, with their authority belonging to that of their originating server. (Publicly facing content SHOULD use HTTPS URIs).
- null
Does this mean an Actor ID can be resolvable through some protocol other than http? E.g, DNS?