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"
  }
}