Cross-Version Extension for MedicationStatement.dosage.asNeeded[x] in R2

Context of Use

This extension may be used in the following contexts:

Name	Flags	Card.	Type	Description & Constraints
Extension		0..1	Extension	Take "as needed" (for x)
extension		..0
value[x]		1..
url				"http://hl7.org/fhir/1.0/StructureDefinition/extension-MedicationStatement.dosage.asNeeded[x]"
Documentation for this format

{
  "resourceType" : "StructureDefinition",
  "id" : "xv-r2-mst.dos.asNeeded[x]",
  "url" : "http://hl7.org/fhir/1.0/StructureDefinition/extension-MedicationStatement.dosage.asNeeded[x]",
  "name" : "XVerExtensionMedicationStatement.dosage.asNeeded[x]R2",
  "title" : "Cross-Version Extension for MedicationStatement.dosage.asNeeded[x] in R2",
  "status" : "active",
  "experimental" : false,
  "publisher" : "Health Level Seven International (Pharmacy)",
  "contact" : [{
    "telecom" : [{
      "system" : "other",
      "value" : "http://hl7.org/fhir"
    }]
  },
  {
    "telecom" : [{
      "system" : "other",
      "value" : "http://www.hl7.org/Special/committees/medication/index.cfm"
    }]
  }],
  "description" : "Cross-Version Extension for MedicationStatement.dosage.asNeeded[x]. Valid in versions null\r\n\r\nThis is a valid cross-version extension because it has a parent that can be an extension in at least one version",
  "jurisdiction" : [{
    "coding" : [{
      "system" : "http://unstats.un.org/unsd/methods/m49/m49.htm",
      "code" : "001"
    }]
  }],
  "fhirVersion" : "5.0.0",
  "kind" : "complex-type",
  "abstract" : false,
  "type" : "Extension",
  "baseDefinition" : "http://hl7.org/fhir/StructureDefinition/Extension",
  "derivation" : "constraint",
  "differential" : {
    "element" : [{
      "path" : "Extension",
      "short" : "Take \"as needed\" (for x)",
      "definition" : "Indicates whether the Medication is only taken when needed within a specific dosing schedule (Boolean option), or it indicates the precondition for taking the Medication (CodeableConcept).    Specifically if 'boolean' datatype is selected, then the following logic applies:  If set to True, this indicates that the medication is only taken when needed, within the specified schedule.",
      "min" : 0,
      "max" : "1",
      "isModifier" : false,
      "mapping" : [{
        "identity" : "rim",
        "map" : "boolean: .outboundRelationship[typeCode=PRCN].negationInd (inversed - so negationInd = true means asNeeded=false  CodeableConcept: .outboundRelationship[typCode=PRCN].target[classCode=OBS, moodCode=EVN, isCriterionInd=true, code=\"Assertion\"].value"
      }]
    },
    {
      "path" : "Extension.extension",
      "max" : "0"
    },
    {
      "path" : "Extension.value[x]",
      "min" : 1
    },
    {
      "path" : "Extension.url",
      "fixedUri" : "http://hl7.org/fhir/1.0/StructureDefinition/extension-MedicationStatement.dosage.asNeeded[x]"
    }]
  }
}