If a recipient is a Collection or OrderedCollection, then the server MUST dereference the collection (with the user's credentials) and discover inboxes for each item in the collection.

{
  "id": "urn:uuid:66d5b416-7660-48c8-884b-fda5e26b28e8",
  "uuid": "66d5b416-7660-48c8-884b-fda5e26b28e8",
  "type": "Behavior",
  "content": "If a recipient is a Collection or OrderedCollection, then the server MUST dereference the collection (with the user's credentials) and discover inboxes for each item in the collection.\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": "The inbox is determined by first retrieving the target actor's JSON-LD representation and then looking up the inbox property.\n",
      "exact": "If a recipient is a Collection or OrderedCollection, then the server MUST dereference the collection (with the user's credentials) and discover inboxes for each item in the collection.\n",
      "suffix": "Servers MUST limit the number of layers of indirections through collections which will be performed, which MAY be one.\n"
    }
  },
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    "https://socialweb.coop/ns/testing/context.json"
  ]
}