Servers MUST also exclude actors from the list which are the same as the actor of the Activity being notified about.

Requirement

Servers MUST also exclude actors from the list which are the same as the actor of the Activity being notified about.

Origin

The origin of this requirement is a quote from the ActivityPub specfiication:
prefixServers MUST de-duplicate the final recipient list.
Servers MUST also exclude actors from the list which are the same as the actor of the Activity being notified about.
suffix That is, actors shouldn't have their own activities delivered to themselves.
https://www.w3.org/TR/activitypub/ , § 7.1

id

urn:uuid:4592b2b2-9f47-4db6-a0a1-e7ba637b002e

uuid

4592b2b2-9f47-4db6-a0a1-e7ba637b002e

Full JSON

{
  "id": "urn:uuid:4592b2b2-9f47-4db6-a0a1-e7ba637b002e",
  "uuid": "4592b2b2-9f47-4db6-a0a1-e7ba637b002e",
  "type": "Behavior",
  "content": "Servers MUST also exclude actors from the list which are the same as the actor of the Activity being notified about.\n",
  "tag": [
    {
      "name": "ActivityPubServer",
      "id": "https://socialweb.coop/tag/ActivityPubServer"
    }
  ],
  "context": [
    "https://www.w3.org/TR/activitypub/",
    {
      "name": "7. Server to Server Interactions",
      "id": "https://www.w3.org/TR/activitypub/#server-to-server-interactions"
    },
    {
      "name": "7.1 Delivery",
      "id": "https://www.w3.org/TR/activitypub/#delivery"
    }
  ],
  "origin": {
    "source": "https://www.w3.org/TR/activitypub/",
    "section": {
      "id": "https://www.w3.org/TR/activitypub/#delivery",
      "branch": [
        7,
        1
      ]
    },
    "selector": {
      "type": "TextQuoteSelector",
      "prefix": "Servers MUST de-duplicate the final recipient list.\n",
      "exact": "Servers MUST also exclude actors from the list which are the same as the actor of the Activity being notified about.\n",
      "suffix": "That is, actors shouldn't have their own activities delivered to themselves.\n"
    }
  },
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    "https://socialweb.coop/ns/testing/context.json"
  ]
}

Links