Options for relationships with additional properties

extra-fields-as-extended-properties.json

{
  "type": "relationship",
  "id": "example.com:relationship:7bc8d066-acc2-4bfb-bc08-acbeb0f52c6b",
  "producer_ref": "example.com:information-source:example",
  "created_at": "2014-05-08T09:00:00.000000+00:00",
  "source_ref": "example.com:incident:dd955e08-16d0-6f08-5064-50d9e7a3104d",
  "target_ref": "example.com:asset:a0777daa-84bf-41e7-89a2-30d7ebb8018d",
  "extended_properties": [
    {
      "type": "incident-impact-extension",
      "confidentiality": "low",
      "integrity": "medium",
      "availability": "medium"
    }
  ], 
  "value": "affected-asset",
  "credibility": 5
}

extra-fields-as-subtype.json

{
  "type": "affected-asset",
  "id": "example.com:relationship:7bc8d066-acc2-4bfb-bc08-acbeb0f52c6b",
  "producer_ref": "example.com:information-source:example",
  "created_at": "2014-05-08T09:00:00.000000+00:00",
  "source_ref": "example.com:incident:dd955e08-16d0-6f08-5064-50d9e7a3104d",
  "target_ref": "example.com:asset:a0777daa-84bf-41e7-89a2-30d7ebb8018d",
  "impact": {
    "confidentiality": "low",
    "integrity": "medium",
    "availability": "medium"
  },
  "value": "affected-asset",
  "credibility": 5
}