{
  "description": "References a location within a set of source text from which the discrete information described by this Resource/Element was extracted.",
  "_filename": "StructureDefinition-derivation-reference.json",
  "package_name": "hl7.fhir.uv.extensions",
  "date": "2020-01-18",
  "derivation": "constraint",
  "publisher": "HL7 International / FHIR Infrastructure",
  "fhirVersion": "5.0.0",
  "jurisdiction": [ {
    "coding": [ {
      "code": "001",
      "system": "http://unstats.un.org/unsd/methods/m49/m49.htm"
    } ]
  } ],
  "name": "ResourceDerivationReference",
  "mapping": [ {
    "uri": "http://hl7.org/v3",
    "name": "RIM Mapping",
    "identity": "rim"
  } ],
  "abstract": false,
  "type": "Extension",
  "experimental": "false",
  "resourceType": "StructureDefinition",
  "title": "Resource Derivation Reference",
  "package_version": "1.0.0",
  "extension": [ {
    "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-wg",
    "valueCode": "fhir"
  }, {
    "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm",
    "valueInteger": 2
  }, {
    "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status",
    "valueCode": "trial-use"
  } ],
  "snapshot": {
    "element": [ {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      }, {
        "key": "ext-1",
        "human": "Must have either extensions or value[x], not both",
        "source": "http://hl7.org/fhir/StructureDefinition/Extension",
        "severity": "error",
        "expression": "extension.exists() != value.exists()"
      }, {
        "key": "der-1",
        "human": "Cannot have length if offset is missing.",
        "source": "http://hl7.org/fhir/StructureDefinition/derivation-reference",
        "severity": "error",
        "expression": "extension.where(url='length').exists() implies extension.where(url='offset').exists()"
      } ],
      "path": "Extension",
      "min": 0,
      "definition": "References a location within a set of source text from which the discrete information described by this Resource/Element was extracted.",
      "isModifier": false,
      "short": "References a location within a set of source text from which the discrete information described by this Resource/Element was extracted.",
      "max": "*",
      "id": "Extension",
      "base": {
        "max": "*",
        "min": 0,
        "path": "Extension"
      }
    }, {
      "path": "Extension.id",
      "min": 0,
      "definition": "Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.",
      "isModifier": false,
      "short": "Unique id for inter-element referencing",
      "mapping": [ {
        "map": "n/a",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "http://hl7.org/fhirpath/System.String",
        "extension": [ {
          "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
          "valueUrl": "id"
        } ]
      } ],
      "representation": [ "xmlAttr" ],
      "max": "1",
      "id": "Extension.id",
      "condition": [ "ele-1" ],
      "base": {
        "max": "1",
        "min": 0,
        "path": "Element.id"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      }, {
        "key": "ext-1",
        "human": "Must have either extensions or value[x], not both",
        "source": "http://hl7.org/fhir/StructureDefinition/Extension",
        "severity": "error",
        "expression": "extension.exists() != value.exists()"
      } ],
      "path": "Extension.extension",
      "min": 0,
      "definition": "May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.",
      "isModifier": false,
      "short": "Additional content defined by implementations",
      "mapping": [ {
        "map": "n/a",
        "identity": "rim"
      } ],
      "slicing": {
        "rules": "open",
        "description": "Extensions are always sliced by (at least) url",
        "discriminator": [ {
          "path": "url",
          "type": "value"
        } ]
      },
      "type": [ {
        "code": "Extension"
      } ],
      "alias": [ "extensions", "user content" ],
      "max": "*",
      "id": "Extension.extension",
      "comment": "There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.",
      "base": {
        "max": "*",
        "min": 0,
        "path": "Element.extension"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      }, {
        "key": "ext-1",
        "human": "Must have either extensions or value[x], not both",
        "source": "http://hl7.org/fhir/StructureDefinition/Extension",
        "severity": "error",
        "expression": "extension.exists() != value.exists()"
      } ],
      "path": "Extension.extension",
      "min": 0,
      "definition": "References a location within a set of source text from which the discrete information described by this Resource/Element was extracted.",
      "isModifier": false,
      "short": "Source reference.",
      "type": [ {
        "code": "Extension"
      } ],
      "sliceName": "reference",
      "max": "1",
      "id": "Extension.extension:reference",
      "base": {
        "max": "*",
        "min": 0,
        "path": "Element.extension"
      },
      "isSummary": false
    }, {
      "path": "Extension.extension.id",
      "min": 0,
      "definition": "Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.",
      "isModifier": false,
      "short": "Unique id for inter-element referencing",
      "mapping": [ {
        "map": "n/a",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "http://hl7.org/fhirpath/System.String",
        "extension": [ {
          "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
          "valueUrl": "id"
        } ]
      } ],
      "representation": [ "xmlAttr" ],
      "max": "1",
      "id": "Extension.extension:reference.id",
      "condition": [ "ele-1" ],
      "base": {
        "max": "1",
        "min": 0,
        "path": "Element.id"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      }, {
        "key": "ext-1",
        "human": "Must have either extensions or value[x], not both",
        "source": "http://hl7.org/fhir/StructureDefinition/Extension",
        "severity": "error",
        "expression": "extension.exists() != value.exists()"
      } ],
      "path": "Extension.extension.extension",
      "min": 0,
      "definition": "An Extension",
      "isModifier": false,
      "short": "Extension",
      "slicing": {
        "rules": "open",
        "description": "Extensions are always sliced by (at least) url",
        "discriminator": [ {
          "path": "url",
          "type": "value"
        } ]
      },
      "type": [ {
        "code": "Extension"
      } ],
      "max": "0",
      "id": "Extension.extension:reference.extension",
      "base": {
        "max": "*",
        "min": 0,
        "path": "Element.extension"
      },
      "isSummary": false
    }, {
      "path": "Extension.extension.url",
      "min": 1,
      "definition": "Source of the definition for the extension code - a logical name or a URL.",
      "isModifier": false,
      "short": "identifies the meaning of the extension",
      "fixedUri": "reference",
      "mapping": [ {
        "map": "N/A",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "http://hl7.org/fhirpath/System.String",
        "extension": [ {
          "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
          "valueUrl": "uri"
        } ]
      } ],
      "representation": [ "xmlAttr" ],
      "max": "1",
      "id": "Extension.extension:reference.url",
      "comment": "The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.",
      "base": {
        "max": "1",
        "min": 1,
        "path": "Extension.url"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      } ],
      "path": "Extension.extension.value[x]",
      "min": 1,
      "definition": "Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/5.0.0-snapshot3/extensibility.html) for a list).",
      "isModifier": false,
      "short": "Value of extension",
      "mapping": [ {
        "map": "N/A",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "Reference"
      } ],
      "max": "1",
      "id": "Extension.extension:reference.value[x]",
      "condition": [ "ext-1" ],
      "base": {
        "max": "1",
        "min": 0,
        "path": "Extension.value[x]"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      }, {
        "key": "ext-1",
        "human": "Must have either extensions or value[x], not both",
        "source": "http://hl7.org/fhir/StructureDefinition/Extension",
        "severity": "error",
        "expression": "extension.exists() != value.exists()"
      } ],
      "path": "Extension.extension",
      "min": 0,
      "definition": "Corresponds to the element within the resource containing the text.",
      "isModifier": false,
      "short": "Element containing text.",
      "type": [ {
        "code": "Extension"
      } ],
      "sliceName": "path",
      "max": "1",
      "id": "Extension.extension:path",
      "comment": "Follows the FHIRPath expression syntax used for OperationOutcome. If not present, then the resource must either be a Binary or a DocumentReference (with a single content element) and the content is the text represented by the instance or the attachment.  If the DocumentReference has more than one 'content', then this path element SHALL be present to distinguish which repetition the derivation occurred from.",
      "base": {
        "max": "*",
        "min": 0,
        "path": "Element.extension"
      },
      "isSummary": false
    }, {
      "path": "Extension.extension.id",
      "min": 0,
      "definition": "Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.",
      "isModifier": false,
      "short": "Unique id for inter-element referencing",
      "mapping": [ {
        "map": "n/a",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "http://hl7.org/fhirpath/System.String",
        "extension": [ {
          "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
          "valueUrl": "id"
        } ]
      } ],
      "representation": [ "xmlAttr" ],
      "max": "1",
      "id": "Extension.extension:path.id",
      "condition": [ "ele-1" ],
      "base": {
        "max": "1",
        "min": 0,
        "path": "Element.id"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      }, {
        "key": "ext-1",
        "human": "Must have either extensions or value[x], not both",
        "source": "http://hl7.org/fhir/StructureDefinition/Extension",
        "severity": "error",
        "expression": "extension.exists() != value.exists()"
      } ],
      "path": "Extension.extension.extension",
      "min": 0,
      "definition": "An Extension",
      "isModifier": false,
      "short": "Extension",
      "slicing": {
        "rules": "open",
        "description": "Extensions are always sliced by (at least) url",
        "discriminator": [ {
          "path": "url",
          "type": "value"
        } ]
      },
      "type": [ {
        "code": "Extension"
      } ],
      "max": "0",
      "id": "Extension.extension:path.extension",
      "base": {
        "max": "*",
        "min": 0,
        "path": "Element.extension"
      },
      "isSummary": false
    }, {
      "path": "Extension.extension.url",
      "min": 1,
      "definition": "Source of the definition for the extension code - a logical name or a URL.",
      "isModifier": false,
      "short": "identifies the meaning of the extension",
      "fixedUri": "path",
      "mapping": [ {
        "map": "N/A",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "http://hl7.org/fhirpath/System.String",
        "extension": [ {
          "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
          "valueUrl": "uri"
        } ]
      } ],
      "representation": [ "xmlAttr" ],
      "max": "1",
      "id": "Extension.extension:path.url",
      "comment": "The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.",
      "base": {
        "max": "1",
        "min": 1,
        "path": "Extension.url"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      } ],
      "path": "Extension.extension.value[x]",
      "min": 1,
      "definition": "Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/5.0.0-snapshot3/extensibility.html) for a list).",
      "isModifier": false,
      "short": "Value of extension",
      "mapping": [ {
        "map": "N/A",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "string"
      } ],
      "max": "1",
      "id": "Extension.extension:path.value[x]",
      "condition": [ "ext-1" ],
      "base": {
        "max": "1",
        "min": 0,
        "path": "Extension.value[x]"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      }, {
        "key": "ext-1",
        "human": "Must have either extensions or value[x], not both",
        "source": "http://hl7.org/fhir/StructureDefinition/Extension",
        "severity": "error",
        "expression": "extension.exists() != value.exists()"
      } ],
      "path": "Extension.extension",
      "min": 0,
      "definition": "Indicates the starting position (as a count of characters) within the text where the relevant derivation began.",
      "isModifier": false,
      "short": "Starting position.",
      "type": [ {
        "code": "Extension"
      } ],
      "sliceName": "offset",
      "max": "1",
      "id": "Extension.extension:offset",
      "base": {
        "max": "*",
        "min": 0,
        "path": "Element.extension"
      },
      "isSummary": false
    }, {
      "path": "Extension.extension.id",
      "min": 0,
      "definition": "Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.",
      "isModifier": false,
      "short": "Unique id for inter-element referencing",
      "mapping": [ {
        "map": "n/a",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "http://hl7.org/fhirpath/System.String",
        "extension": [ {
          "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
          "valueUrl": "id"
        } ]
      } ],
      "representation": [ "xmlAttr" ],
      "max": "1",
      "id": "Extension.extension:offset.id",
      "condition": [ "ele-1" ],
      "base": {
        "max": "1",
        "min": 0,
        "path": "Element.id"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      }, {
        "key": "ext-1",
        "human": "Must have either extensions or value[x], not both",
        "source": "http://hl7.org/fhir/StructureDefinition/Extension",
        "severity": "error",
        "expression": "extension.exists() != value.exists()"
      } ],
      "path": "Extension.extension.extension",
      "min": 0,
      "definition": "An Extension",
      "isModifier": false,
      "short": "Extension",
      "slicing": {
        "rules": "open",
        "description": "Extensions are always sliced by (at least) url",
        "discriminator": [ {
          "path": "url",
          "type": "value"
        } ]
      },
      "type": [ {
        "code": "Extension"
      } ],
      "max": "0",
      "id": "Extension.extension:offset.extension",
      "base": {
        "max": "*",
        "min": 0,
        "path": "Element.extension"
      },
      "isSummary": false
    }, {
      "path": "Extension.extension.url",
      "min": 1,
      "definition": "Source of the definition for the extension code - a logical name or a URL.",
      "isModifier": false,
      "short": "identifies the meaning of the extension",
      "fixedUri": "offset",
      "mapping": [ {
        "map": "N/A",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "http://hl7.org/fhirpath/System.String",
        "extension": [ {
          "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
          "valueUrl": "uri"
        } ]
      } ],
      "representation": [ "xmlAttr" ],
      "max": "1",
      "id": "Extension.extension:offset.url",
      "comment": "The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.",
      "base": {
        "max": "1",
        "min": 1,
        "path": "Extension.url"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      } ],
      "path": "Extension.extension.value[x]",
      "min": 1,
      "definition": "Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/5.0.0-snapshot3/extensibility.html) for a list).",
      "isModifier": false,
      "short": "Value of extension",
      "mapping": [ {
        "map": "N/A",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "integer"
      } ],
      "max": "1",
      "id": "Extension.extension:offset.value[x]",
      "condition": [ "ext-1" ],
      "base": {
        "max": "1",
        "min": 0,
        "path": "Extension.value[x]"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      }, {
        "key": "ext-1",
        "human": "Must have either extensions or value[x], not both",
        "source": "http://hl7.org/fhir/StructureDefinition/Extension",
        "severity": "error",
        "expression": "extension.exists() != value.exists()"
      } ],
      "path": "Extension.extension",
      "min": 0,
      "definition": "Indicates the number of characters following the start position/beginning of the document that was used as part of the derivation process.",
      "isModifier": false,
      "short": "Number of characters.",
      "type": [ {
        "code": "Extension"
      } ],
      "sliceName": "length",
      "max": "1",
      "id": "Extension.extension:length",
      "base": {
        "max": "*",
        "min": 0,
        "path": "Element.extension"
      },
      "isSummary": false
    }, {
      "path": "Extension.extension.id",
      "min": 0,
      "definition": "Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.",
      "isModifier": false,
      "short": "Unique id for inter-element referencing",
      "mapping": [ {
        "map": "n/a",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "http://hl7.org/fhirpath/System.String",
        "extension": [ {
          "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
          "valueUrl": "id"
        } ]
      } ],
      "representation": [ "xmlAttr" ],
      "max": "1",
      "id": "Extension.extension:length.id",
      "condition": [ "ele-1" ],
      "base": {
        "max": "1",
        "min": 0,
        "path": "Element.id"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      }, {
        "key": "ext-1",
        "human": "Must have either extensions or value[x], not both",
        "source": "http://hl7.org/fhir/StructureDefinition/Extension",
        "severity": "error",
        "expression": "extension.exists() != value.exists()"
      } ],
      "path": "Extension.extension.extension",
      "min": 0,
      "definition": "An Extension",
      "isModifier": false,
      "short": "Extension",
      "slicing": {
        "rules": "open",
        "description": "Extensions are always sliced by (at least) url",
        "discriminator": [ {
          "path": "url",
          "type": "value"
        } ]
      },
      "type": [ {
        "code": "Extension"
      } ],
      "max": "0",
      "id": "Extension.extension:length.extension",
      "base": {
        "max": "*",
        "min": 0,
        "path": "Element.extension"
      },
      "isSummary": false
    }, {
      "path": "Extension.extension.url",
      "min": 1,
      "definition": "Source of the definition for the extension code - a logical name or a URL.",
      "isModifier": false,
      "short": "identifies the meaning of the extension",
      "fixedUri": "length",
      "mapping": [ {
        "map": "N/A",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "http://hl7.org/fhirpath/System.String",
        "extension": [ {
          "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
          "valueUrl": "uri"
        } ]
      } ],
      "representation": [ "xmlAttr" ],
      "max": "1",
      "id": "Extension.extension:length.url",
      "comment": "The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.",
      "base": {
        "max": "1",
        "min": 1,
        "path": "Extension.url"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      } ],
      "path": "Extension.extension.value[x]",
      "min": 1,
      "definition": "Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/5.0.0-snapshot3/extensibility.html) for a list).",
      "isModifier": false,
      "short": "Value of extension",
      "mapping": [ {
        "map": "N/A",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "integer"
      } ],
      "max": "1",
      "id": "Extension.extension:length.value[x]",
      "condition": [ "ext-1" ],
      "base": {
        "max": "1",
        "min": 0,
        "path": "Extension.value[x]"
      },
      "isSummary": false
    }, {
      "path": "Extension.url",
      "min": 1,
      "definition": "Source of the definition for the extension code - a logical name or a URL.",
      "isModifier": false,
      "short": "identifies the meaning of the extension",
      "fixedUri": "http://hl7.org/fhir/StructureDefinition/derivation-reference",
      "mapping": [ {
        "map": "N/A",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "http://hl7.org/fhirpath/System.String",
        "extension": [ {
          "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
          "valueUrl": "uri"
        } ]
      } ],
      "representation": [ "xmlAttr" ],
      "max": "1",
      "id": "Extension.url",
      "comment": "The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.",
      "base": {
        "max": "1",
        "min": 1,
        "path": "Extension.url"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      } ],
      "path": "Extension.value[x]",
      "min": 0,
      "definition": "Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/5.0.0-snapshot3/extensibility.html) for a list).",
      "isModifier": false,
      "short": "Value of extension",
      "mapping": [ {
        "map": "N/A",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "base64Binary"
      }, {
        "code": "boolean"
      }, {
        "code": "canonical"
      }, {
        "code": "code"
      }, {
        "code": "date"
      }, {
        "code": "dateTime"
      }, {
        "code": "decimal"
      }, {
        "code": "id"
      }, {
        "code": "instant"
      }, {
        "code": "integer"
      }, {
        "code": "integer64"
      }, {
        "code": "markdown"
      }, {
        "code": "oid"
      }, {
        "code": "positiveInt"
      }, {
        "code": "string"
      }, {
        "code": "time"
      }, {
        "code": "unsignedInt"
      }, {
        "code": "uri"
      }, {
        "code": "url"
      }, {
        "code": "uuid"
      }, {
        "code": "Address"
      }, {
        "code": "Age"
      }, {
        "code": "Annotation"
      }, {
        "code": "Attachment"
      }, {
        "code": "CodeableConcept"
      }, {
        "code": "CodeableReference"
      }, {
        "code": "Coding"
      }, {
        "code": "ContactPoint"
      }, {
        "code": "Count"
      }, {
        "code": "Distance"
      }, {
        "code": "Duration"
      }, {
        "code": "HumanName"
      }, {
        "code": "Identifier"
      }, {
        "code": "Money"
      }, {
        "code": "Period"
      }, {
        "code": "Quantity"
      }, {
        "code": "Range"
      }, {
        "code": "Ratio"
      }, {
        "code": "RatioRange"
      }, {
        "code": "Reference"
      }, {
        "code": "SampledData"
      }, {
        "code": "Signature"
      }, {
        "code": "Timing"
      }, {
        "code": "ContactDetail"
      }, {
        "code": "DataRequirement"
      }, {
        "code": "Expression"
      }, {
        "code": "ParameterDefinition"
      }, {
        "code": "RelatedArtifact"
      }, {
        "code": "TriggerDefinition"
      }, {
        "code": "UsageContext"
      }, {
        "code": "Availability"
      }, {
        "code": "ExtendedContactDetail"
      }, {
        "code": "Dosage"
      }, {
        "code": "Meta"
      } ],
      "max": "0",
      "id": "Extension.value[x]",
      "condition": [ "ext-1" ],
      "base": {
        "max": "1",
        "min": 0,
        "path": "Extension.value[x]"
      },
      "isSummary": false
    } ]
  },
  "status": "draft",
  "id": "3454e8fb-17d4-4e15-a261-10a054e77aeb",
  "kind": "complex-type",
  "url": "http://hl7.org/fhir/StructureDefinition/derivation-reference",
  "identifier": [ {
    "value": "urn:oid:2.16.840.1.113883.4.642.5.1425",
    "system": "urn:ietf:rfc:3986"
  } ],
  "context": [ {
    "type": "element",
    "expression": "Resource"
  }, {
    "type": "element",
    "expression": "Element"
  } ],
  "version": "1.0.0",
  "differential": {
    "element": [ {
      "id": "Extension",
      "path": "Extension",
      "short": "References a location within a set of source text from which the discrete information described by this Resource/Element was extracted.",
      "constraint": [ {
        "key": "der-1",
        "human": "Cannot have length if offset is missing.",
        "source": "http://hl7.org/fhir/StructureDefinition/derivation-reference",
        "severity": "error",
        "expression": "extension.where(url='length').exists() implies extension.where(url='offset').exists()"
      } ],
      "definition": "References a location within a set of source text from which the discrete information described by this Resource/Element was extracted."
    }, {
      "id": "Extension.extension:reference",
      "max": "1",
      "min": 0,
      "path": "Extension.extension",
      "short": "Source reference.",
      "sliceName": "reference",
      "definition": "References a location within a set of source text from which the discrete information described by this Resource/Element was extracted."
    }, {
      "id": "Extension.extension:reference.extension",
      "max": "0",
      "path": "Extension.extension.extension"
    }, {
      "id": "Extension.extension:reference.url",
      "path": "Extension.extension.url",
      "fixedUri": "reference"
    }, {
      "id": "Extension.extension:reference.value[x]",
      "min": 1,
      "path": "Extension.extension.value[x]",
      "type": [ {
        "code": "Reference"
      } ]
    }, {
      "id": "Extension.extension:path",
      "max": "1",
      "min": 0,
      "path": "Extension.extension",
      "short": "Element containing text.",
      "comment": "Follows the FHIRPath expression syntax used for OperationOutcome. If not present, then the resource must either be a Binary or a DocumentReference (with a single content element) and the content is the text represented by the instance or the attachment.  If the DocumentReference has more than one 'content', then this path element SHALL be present to distinguish which repetition the derivation occurred from.",
      "sliceName": "path",
      "definition": "Corresponds to the element within the resource containing the text."
    }, {
      "id": "Extension.extension:path.extension",
      "max": "0",
      "path": "Extension.extension.extension"
    }, {
      "id": "Extension.extension:path.url",
      "path": "Extension.extension.url",
      "fixedUri": "path"
    }, {
      "id": "Extension.extension:path.value[x]",
      "min": 1,
      "path": "Extension.extension.value[x]",
      "type": [ {
        "code": "string"
      } ]
    }, {
      "id": "Extension.extension:offset",
      "max": "1",
      "min": 0,
      "path": "Extension.extension",
      "short": "Starting position.",
      "sliceName": "offset",
      "definition": "Indicates the starting position (as a count of characters) within the text where the relevant derivation began.",
      "meaningWhenMissing": "If not specified, the location at which derivation started is unknown."
    }, {
      "id": "Extension.extension:offset.extension",
      "max": "0",
      "path": "Extension.extension.extension"
    }, {
      "id": "Extension.extension:offset.url",
      "path": "Extension.extension.url",
      "fixedUri": "offset"
    }, {
      "id": "Extension.extension:offset.value[x]",
      "min": 1,
      "path": "Extension.extension.value[x]",
      "type": [ {
        "code": "integer"
      } ]
    }, {
      "id": "Extension.extension:length",
      "max": "1",
      "min": 0,
      "path": "Extension.extension",
      "short": "Number of characters.",
      "sliceName": "length",
      "definition": "Indicates the number of characters following the start position/beginning of the document that was used as part of the derivation process.",
      "meaningWhenMissing": "If not specified, the location at which derivation ended is unknown."
    }, {
      "id": "Extension.extension:length.extension",
      "max": "0",
      "path": "Extension.extension.extension"
    }, {
      "id": "Extension.extension:length.url",
      "path": "Extension.extension.url",
      "fixedUri": "length"
    }, {
      "id": "Extension.extension:length.value[x]",
      "min": 1,
      "path": "Extension.extension.value[x]",
      "type": [ {
        "code": "integer"
      } ]
    }, {
      "id": "Extension.url",
      "path": "Extension.url",
      "fixedUri": "http://hl7.org/fhir/StructureDefinition/derivation-reference"
    }, {
      "id": "Extension.value[x]",
      "max": "0",
      "path": "Extension.value[x]"
    } ]
  },
  "contact": [ {
    "telecom": [ {
      "value": "http://hl7.org/Special/committees/fhir-i",
      "system": "url"
    } ]
  } ],
  "baseDefinition": "http://hl7.org/fhir/StructureDefinition/Extension"
}