How 'basic' can be used for future resources - in this case referral

{
  "resourceType": "Basic",
  "id": "referral",
  "text": {
    "status": "generated",
    "div": "<div xmlns=\"http://www.w3.org/1999/xhtml\">\n      <p><b>Patient:</b>Roel</p>\n      <p><b>Requestor:</b>Dokter Bronsig</p>\n      <p><b>Type:</b>Consultation</p>\n      <p><b>Target Date:</b>April 1 - April 31</p>\n      <p>COMPLETED</p>\n      <b>The patient had fever peaks over the last couple of days. He is worried about these peaks.</b>\n    </div>"
  },
  "extension": [
    {
      "url": "http://example.org/do-not-use/fhir-extensions/referral#requestingPractitioner",
      "valueReference": {
        "reference": "Practitioner/f201",
        "display": "Dokter Bronsig"
      }
    },
    {
      "url": "http://example.org/do-not-use/fhir-extensions/referral#notes",
      "valueString": "The patient had fever peaks over the last couple of days. He is worried about these peaks."
    },
    {
      "url": "http://example.org/do-not-use/fhir-extensions/referral#fulfillingEncounter",
      "valueReference": {
        "reference": "Encounter/f201"
      }
    }
  ],
  "modifierExtension": [
    {
      "url": "http://example.org/do-not-use/fhir-extensions/referral#referredForService",
      "valueCodeableConcept": {
        "coding": [
          {
            "system": "http://snomed.info/sct",
            "code": "11429006",
            "display": "Consultation"
          }
        ]
      }
    },
    {
      "url": "http://example.org/do-not-use/fhir-extensions/referral#targetDate",
      "valuePeriod": {
        "start": "2013-04-01",
        "end": "2013-04-15"
      }
    },
    {
      "url": "http://example.org/do-not-use/fhir-extensions/referral#status",
      "valueCode": "complete"
    }
  ],
  "identifier": [
    {
      "system": "http://goodhealth.org/basic/identifiers",
      "value": "19283746"
    }
  ],
  "code": {
    "coding": [
      {
        "system": "http://terminology.hl7.org/CodeSystem/basic-resource-type",
        "code": "referral"
      }
    ]
  },
  "subject": {
    "reference": "Patient/f201",
    "display": "Roel"
  },
  "created": "2013-05-14",
  "author": {
    "reference": "Practitioner/example"
  }
}