{
  "resourceType": "StructureDefinition",
  "id": "nexus-requisition-signature",
  "url": "https://fhir.apps.health/StructureDefinition/nexus-requisition-signature",
  "name": "NexusRequisitionSignature",
  "title": "Requisition Signature Extension",
  "status": "draft",
  "description": "The clinician's electronic signature on a laboratory requisition: who signed it, and when.\n\n**An attestation, not a cryptographic signature -- and R4's `Signature` datatype is built for\nexactly that.** Its `type` binds ISO/ASTM E1762 attestation kinds (`Author's Signature` among them)\nrather than algorithms, and `data` is optional, so a signature with no digest and no key is valid.\nA future revision of this extension carries a `Signature` as its value for that reason; what follows\ndescribes the shape written today. This is not the R4 `Signature` datatype and\ncarries no digest, no signed blob and no key. It records that the authenticated user asserted the\nrequisition at a moment in time. A consumer must not present it as a verifiable cryptographic\nsignature.\n\n**Presence is the flag.** There is no separate stored boolean. A requisition carrying this\nextension is signed; one without it is not.\n\n**At most one, and a re-sign replaces it.** The form prints one signature line. The sequence of\nsignings is read from the resource's version history, where each stored version carries the\nsignature it was written with and, separately, the reason that version was written.\n\n**The signer's name is stored on the reference, deliberately.** `signer.display` is the name as it\nprinted on the sheet when it was signed. A reprint must reproduce the issued document from the\nresource alone, so a later change to the practitioner's recorded name does not change what an\nalready-issued requisition says.\n\n**No stamp image is referenced.** A signature prints as the typed name. The `stamp` child below is\nread-only legacy and must never be produced; its absence carries no meaning about validity.",
  "fhirVersion": "4.0.1",
  "mapping": [
    {
      "identity": "rim",
      "uri": "http://hl7.org/v3",
      "name": "RIM Mapping"
    }
  ],
  "kind": "complex-type",
  "abstract": false,
  "context": [
    {
      "type": "element",
      "expression": "ServiceRequest"
    }
  ],
  "type": "Extension",
  "baseDefinition": "http://hl7.org/fhir/StructureDefinition/Extension",
  "derivation": "constraint",
  "snapshot": {
    "element": [
      {
        "id": "Extension",
        "path": "Extension",
        "short": "The clinician's electronic signature on the requisition -- who, and when",
        "definition": "The clinician's electronic signature on a laboratory requisition: who signed it, and when.\n\n**An attestation, not a cryptographic signature -- and R4's `Signature` datatype is built for\nexactly that.** Its `type` binds ISO/ASTM E1762 attestation kinds (`Author's Signature` among them)\nrather than algorithms, and `data` is optional, so a signature with no digest and no key is valid.\nA future revision of this extension carries a `Signature` as its value for that reason; what follows\ndescribes the shape written today. This is not the R4 `Signature` datatype and\ncarries no digest, no signed blob and no key. It records that the authenticated user asserted the\nrequisition at a moment in time. A consumer must not present it as a verifiable cryptographic\nsignature.\n\n**Presence is the flag.** There is no separate stored boolean. A requisition carrying this\nextension is signed; one without it is not.\n\n**At most one, and a re-sign replaces it.** The form prints one signature line. The sequence of\nsignings is read from the resource's version history, where each stored version carries the\nsignature it was written with and, separately, the reason that version was written.\n\n**The signer's name is stored on the reference, deliberately.** `signer.display` is the name as it\nprinted on the sheet when it was signed. A reprint must reproduce the issued document from the\nresource alone, so a later change to the practitioner's recorded name does not change what an\nalready-issued requisition says.\n\n**No stamp image is referenced.** A signature prints as the typed name. The `stamp` child below is\nread-only legacy and must never be produced; its absence carries no meaning about validity.",
        "min": 0,
        "max": "*",
        "base": {
          "path": "Extension",
          "min": 0,
          "max": "*"
        },
        "condition": [
          "ele-1"
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() or (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          },
          {
            "key": "ext-1",
            "severity": "error",
            "human": "Must have either extensions or value[x], not both",
            "expression": "extension.exists() != value.exists()",
            "xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), 'value')])"
          }
        ],
        "isModifier": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          },
          {
            "identity": "rim",
            "map": "N/A"
          }
        ]
      },
      {
        "id": "Extension.id",
        "path": "Extension.id",
        "representation": [
          "xmlAttr"
        ],
        "short": "Unique id for inter-element referencing",
        "definition": "Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.",
        "min": 0,
        "max": "1",
        "base": {
          "path": "Element.id",
          "min": 0,
          "max": "1"
        },
        "type": [
          {
            "code": "http://hl7.org/fhirpath/System.String",
            "extension": [
              {
                "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
                "valueUrl": "string"
              }
            ]
          }
        ],
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          }
        ]
      },
      {
        "id": "Extension.extension",
        "path": "Extension.extension",
        "slicing": {
          "discriminator": [
            {
              "type": "value",
              "path": "url"
            }
          ],
          "description": "Extensions are always sliced by (at least) url",
          "rules": "open"
        },
        "short": "Additional content defined by implementations",
        "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 manageable, 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.",
        "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.",
        "alias": [
          "extensions",
          "user content"
        ],
        "min": 2,
        "max": "*",
        "base": {
          "path": "Element.extension",
          "min": 0,
          "max": "*"
        },
        "type": [
          {
            "code": "Extension"
          }
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() or (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          },
          {
            "key": "ext-1",
            "severity": "error",
            "human": "Must have either extensions or value[x], not both",
            "expression": "extension.exists() != value.exists()",
            "xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), \"value\")])",
            "source": "http://hl7.org/fhir/StructureDefinition/Extension"
          }
        ],
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          }
        ]
      },
      {
        "id": "Extension.extension:signer",
        "path": "Extension.extension",
        "sliceName": "signer",
        "short": "Who signed -- the ordering clinician, as a PractitionerRole where one resolved",
        "definition": "The clinician who signed the requisition. A `PractitionerRole` where the signing context resolved one, otherwise the `Practitioner`. `display` carries the name exactly as it printed on the signed sheet and is stored so a reprint does not change when the practitioner record does.",
        "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.",
        "alias": [
          "extensions",
          "user content"
        ],
        "min": 1,
        "max": "1",
        "base": {
          "path": "Element.extension",
          "min": 0,
          "max": "*"
        },
        "type": [
          {
            "code": "Extension"
          }
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() or (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          },
          {
            "key": "ext-1",
            "severity": "error",
            "human": "Must have either extensions or value[x], not both",
            "expression": "extension.exists() != value.exists()",
            "xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), \"value\")])",
            "source": "http://hl7.org/fhir/StructureDefinition/Extension"
          }
        ],
        "mustSupport": true,
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          }
        ]
      },
      {
        "id": "Extension.extension:signer.id",
        "path": "Extension.extension.id",
        "representation": [
          "xmlAttr"
        ],
        "short": "Unique id for inter-element referencing",
        "definition": "Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.",
        "min": 0,
        "max": "1",
        "base": {
          "path": "Element.id",
          "min": 0,
          "max": "1"
        },
        "type": [
          {
            "code": "http://hl7.org/fhirpath/System.String",
            "extension": [
              {
                "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
                "valueUrl": "string"
              }
            ]
          }
        ],
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          }
        ]
      },
      {
        "id": "Extension.extension:signer.extension",
        "path": "Extension.extension.extension",
        "slicing": {
          "discriminator": [
            {
              "type": "value",
              "path": "url"
            }
          ],
          "description": "Extensions are always sliced by (at least) url",
          "rules": "open"
        },
        "short": "Additional content defined by implementations",
        "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 manageable, 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.",
        "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.",
        "alias": [
          "extensions",
          "user content"
        ],
        "min": 0,
        "max": "0",
        "base": {
          "path": "Element.extension",
          "min": 0,
          "max": "*"
        },
        "type": [
          {
            "code": "Extension"
          }
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() or (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          },
          {
            "key": "ext-1",
            "severity": "error",
            "human": "Must have either extensions or value[x], not both",
            "expression": "extension.exists() != value.exists()",
            "xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), \"value\")])",
            "source": "http://hl7.org/fhir/StructureDefinition/Extension"
          }
        ],
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          }
        ]
      },
      {
        "id": "Extension.extension:signer.url",
        "path": "Extension.extension.url",
        "representation": [
          "xmlAttr"
        ],
        "short": "identifies the meaning of the extension",
        "definition": "Source of the definition for the extension code - a logical name or a 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.",
        "min": 1,
        "max": "1",
        "base": {
          "path": "Extension.url",
          "min": 1,
          "max": "1"
        },
        "type": [
          {
            "code": "http://hl7.org/fhirpath/System.String",
            "extension": [
              {
                "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
                "valueUrl": "uri"
              }
            ]
          }
        ],
        "fixedUri": "signer",
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "N/A"
          }
        ]
      },
      {
        "id": "Extension.extension:signer.value[x]",
        "path": "Extension.extension.value[x]",
        "short": "Value of extension",
        "definition": "Value of extension - must be one of a constrained set of the data types (see [Extensibility](extensibility.html) for a list).",
        "min": 0,
        "max": "1",
        "base": {
          "path": "Extension.value[x]",
          "min": 0,
          "max": "1"
        },
        "type": [
          {
            "code": "Reference",
            "targetProfile": [
              "http://hl7.org/fhir/StructureDefinition/Practitioner",
              "http://hl7.org/fhir/StructureDefinition/PractitionerRole"
            ]
          }
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() or (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          }
        ],
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "N/A"
          }
        ]
      },
      {
        "id": "Extension.extension:signedAt",
        "path": "Extension.extension",
        "sliceName": "signedAt",
        "short": "When the requisition was signed -- a fully-qualified instant",
        "definition": "The moment the requisition was signed, as a timezone-qualified dateTime. This is the time of the signing write, which is not the same as `ServiceRequest.authoredOn`: authoring is preserved across an amendment while the signature is stamped afresh, so the two differ on any requisition that has been edited.",
        "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.",
        "alias": [
          "extensions",
          "user content"
        ],
        "min": 1,
        "max": "1",
        "base": {
          "path": "Element.extension",
          "min": 0,
          "max": "*"
        },
        "type": [
          {
            "code": "Extension"
          }
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() or (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          },
          {
            "key": "ext-1",
            "severity": "error",
            "human": "Must have either extensions or value[x], not both",
            "expression": "extension.exists() != value.exists()",
            "xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), \"value\")])",
            "source": "http://hl7.org/fhir/StructureDefinition/Extension"
          }
        ],
        "mustSupport": true,
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          }
        ]
      },
      {
        "id": "Extension.extension:signedAt.id",
        "path": "Extension.extension.id",
        "representation": [
          "xmlAttr"
        ],
        "short": "Unique id for inter-element referencing",
        "definition": "Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.",
        "min": 0,
        "max": "1",
        "base": {
          "path": "Element.id",
          "min": 0,
          "max": "1"
        },
        "type": [
          {
            "code": "http://hl7.org/fhirpath/System.String",
            "extension": [
              {
                "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
                "valueUrl": "string"
              }
            ]
          }
        ],
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          }
        ]
      },
      {
        "id": "Extension.extension:signedAt.extension",
        "path": "Extension.extension.extension",
        "slicing": {
          "discriminator": [
            {
              "type": "value",
              "path": "url"
            }
          ],
          "description": "Extensions are always sliced by (at least) url",
          "rules": "open"
        },
        "short": "Additional content defined by implementations",
        "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 manageable, 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.",
        "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.",
        "alias": [
          "extensions",
          "user content"
        ],
        "min": 0,
        "max": "0",
        "base": {
          "path": "Element.extension",
          "min": 0,
          "max": "*"
        },
        "type": [
          {
            "code": "Extension"
          }
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() or (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          },
          {
            "key": "ext-1",
            "severity": "error",
            "human": "Must have either extensions or value[x], not both",
            "expression": "extension.exists() != value.exists()",
            "xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), \"value\")])",
            "source": "http://hl7.org/fhir/StructureDefinition/Extension"
          }
        ],
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          }
        ]
      },
      {
        "id": "Extension.extension:signedAt.url",
        "path": "Extension.extension.url",
        "representation": [
          "xmlAttr"
        ],
        "short": "identifies the meaning of the extension",
        "definition": "Source of the definition for the extension code - a logical name or a 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.",
        "min": 1,
        "max": "1",
        "base": {
          "path": "Extension.url",
          "min": 1,
          "max": "1"
        },
        "type": [
          {
            "code": "http://hl7.org/fhirpath/System.String",
            "extension": [
              {
                "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
                "valueUrl": "uri"
              }
            ]
          }
        ],
        "fixedUri": "signedAt",
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "N/A"
          }
        ]
      },
      {
        "id": "Extension.extension:signedAt.value[x]",
        "path": "Extension.extension.value[x]",
        "short": "Value of extension",
        "definition": "Value of extension - must be one of a constrained set of the data types (see [Extensibility](extensibility.html) for a list).",
        "min": 0,
        "max": "1",
        "base": {
          "path": "Extension.value[x]",
          "min": 0,
          "max": "1"
        },
        "type": [
          {
            "code": "dateTime"
          }
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() or (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          }
        ],
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "N/A"
          }
        ]
      },
      {
        "id": "Extension.extension:stamp",
        "path": "Extension.extension",
        "sliceName": "stamp",
        "short": "LEGACY, read-only: identifier of a stored signature-stamp document",
        "definition": "The identifier of a stored document holding the signer's stamp image, as captured at sign time. **Deprecated: no producer writes this, and none should.** It is described because requisitions signed under an earlier shape still carry it and must keep rebuilding exactly as they did. Its absence says nothing about the validity of a signature -- an unstamped signature prints as the typed name and is fully valid.",
        "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.",
        "alias": [
          "extensions",
          "user content"
        ],
        "min": 0,
        "max": "1",
        "base": {
          "path": "Element.extension",
          "min": 0,
          "max": "*"
        },
        "type": [
          {
            "code": "Extension"
          }
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() or (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          },
          {
            "key": "ext-1",
            "severity": "error",
            "human": "Must have either extensions or value[x], not both",
            "expression": "extension.exists() != value.exists()",
            "xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), \"value\")])",
            "source": "http://hl7.org/fhir/StructureDefinition/Extension"
          }
        ],
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          }
        ]
      },
      {
        "id": "Extension.extension:stamp.id",
        "path": "Extension.extension.id",
        "representation": [
          "xmlAttr"
        ],
        "short": "Unique id for inter-element referencing",
        "definition": "Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.",
        "min": 0,
        "max": "1",
        "base": {
          "path": "Element.id",
          "min": 0,
          "max": "1"
        },
        "type": [
          {
            "code": "http://hl7.org/fhirpath/System.String",
            "extension": [
              {
                "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
                "valueUrl": "string"
              }
            ]
          }
        ],
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          }
        ]
      },
      {
        "id": "Extension.extension:stamp.extension",
        "path": "Extension.extension.extension",
        "slicing": {
          "discriminator": [
            {
              "type": "value",
              "path": "url"
            }
          ],
          "description": "Extensions are always sliced by (at least) url",
          "rules": "open"
        },
        "short": "Additional content defined by implementations",
        "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 manageable, 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.",
        "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.",
        "alias": [
          "extensions",
          "user content"
        ],
        "min": 0,
        "max": "0",
        "base": {
          "path": "Element.extension",
          "min": 0,
          "max": "*"
        },
        "type": [
          {
            "code": "Extension"
          }
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() or (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          },
          {
            "key": "ext-1",
            "severity": "error",
            "human": "Must have either extensions or value[x], not both",
            "expression": "extension.exists() != value.exists()",
            "xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), \"value\")])",
            "source": "http://hl7.org/fhir/StructureDefinition/Extension"
          }
        ],
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          }
        ]
      },
      {
        "id": "Extension.extension:stamp.url",
        "path": "Extension.extension.url",
        "representation": [
          "xmlAttr"
        ],
        "short": "identifies the meaning of the extension",
        "definition": "Source of the definition for the extension code - a logical name or a 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.",
        "min": 1,
        "max": "1",
        "base": {
          "path": "Extension.url",
          "min": 1,
          "max": "1"
        },
        "type": [
          {
            "code": "http://hl7.org/fhirpath/System.String",
            "extension": [
              {
                "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
                "valueUrl": "uri"
              }
            ]
          }
        ],
        "fixedUri": "stamp",
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "N/A"
          }
        ]
      },
      {
        "id": "Extension.extension:stamp.value[x]",
        "path": "Extension.extension.value[x]",
        "short": "Value of extension",
        "definition": "Value of extension - must be one of a constrained set of the data types (see [Extensibility](extensibility.html) for a list).",
        "min": 0,
        "max": "1",
        "base": {
          "path": "Extension.value[x]",
          "min": 0,
          "max": "1"
        },
        "type": [
          {
            "code": "string"
          }
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() or (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          }
        ],
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "N/A"
          }
        ]
      },
      {
        "id": "Extension.url",
        "path": "Extension.url",
        "representation": [
          "xmlAttr"
        ],
        "short": "identifies the meaning of the extension",
        "definition": "Source of the definition for the extension code - a logical name or a 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.",
        "min": 1,
        "max": "1",
        "base": {
          "path": "Extension.url",
          "min": 1,
          "max": "1"
        },
        "type": [
          {
            "code": "http://hl7.org/fhirpath/System.String",
            "extension": [
              {
                "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
                "valueUrl": "uri"
              }
            ]
          }
        ],
        "fixedUri": "https://fhir.apps.health/StructureDefinition/nexus-requisition-signature",
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "N/A"
          }
        ]
      },
      {
        "id": "Extension.value[x]",
        "path": "Extension.value[x]",
        "short": "Value of extension",
        "definition": "Value of extension - must be one of a constrained set of the data types (see [Extensibility](extensibility.html) for a list).",
        "min": 0,
        "max": "0",
        "base": {
          "path": "Extension.value[x]",
          "min": 0,
          "max": "1"
        },
        "type": [
          {
            "code": "base64Binary"
          },
          {
            "code": "boolean"
          },
          {
            "code": "canonical"
          },
          {
            "code": "code"
          },
          {
            "code": "date"
          },
          {
            "code": "dateTime"
          },
          {
            "code": "decimal"
          },
          {
            "code": "id"
          },
          {
            "code": "instant"
          },
          {
            "code": "integer"
          },
          {
            "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": "Coding"
          },
          {
            "code": "ContactPoint"
          },
          {
            "code": "Count"
          },
          {
            "code": "Distance"
          },
          {
            "code": "Duration"
          },
          {
            "code": "HumanName"
          },
          {
            "code": "Identifier"
          },
          {
            "code": "Money"
          },
          {
            "code": "Period"
          },
          {
            "code": "Quantity"
          },
          {
            "code": "Range"
          },
          {
            "code": "Ratio"
          },
          {
            "code": "Reference"
          },
          {
            "code": "SampledData"
          },
          {
            "code": "Signature"
          },
          {
            "code": "Timing"
          },
          {
            "code": "ContactDetail"
          },
          {
            "code": "Contributor"
          },
          {
            "code": "DataRequirement"
          },
          {
            "code": "Expression"
          },
          {
            "code": "ParameterDefinition"
          },
          {
            "code": "RelatedArtifact"
          },
          {
            "code": "TriggerDefinition"
          },
          {
            "code": "UsageContext"
          },
          {
            "code": "Dosage"
          },
          {
            "code": "Meta"
          }
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() or (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          }
        ],
        "isModifier": false,
        "isSummary": false,
        "mapping": [
          {
            "identity": "rim",
            "map": "N/A"
          }
        ]
      }
    ]
  },
  "differential": {
    "element": [
      {
        "id": "Extension",
        "path": "Extension",
        "short": "The clinician's electronic signature on the requisition -- who, and when",
        "definition": "The clinician's electronic signature on a laboratory requisition: who signed it, and when.\n\n**An attestation, not a cryptographic signature -- and R4's `Signature` datatype is built for\nexactly that.** Its `type` binds ISO/ASTM E1762 attestation kinds (`Author's Signature` among them)\nrather than algorithms, and `data` is optional, so a signature with no digest and no key is valid.\nA future revision of this extension carries a `Signature` as its value for that reason; what follows\ndescribes the shape written today. This is not the R4 `Signature` datatype and\ncarries no digest, no signed blob and no key. It records that the authenticated user asserted the\nrequisition at a moment in time. A consumer must not present it as a verifiable cryptographic\nsignature.\n\n**Presence is the flag.** There is no separate stored boolean. A requisition carrying this\nextension is signed; one without it is not.\n\n**At most one, and a re-sign replaces it.** The form prints one signature line. The sequence of\nsignings is read from the resource's version history, where each stored version carries the\nsignature it was written with and, separately, the reason that version was written.\n\n**The signer's name is stored on the reference, deliberately.** `signer.display` is the name as it\nprinted on the sheet when it was signed. A reprint must reproduce the issued document from the\nresource alone, so a later change to the practitioner's recorded name does not change what an\nalready-issued requisition says.\n\n**No stamp image is referenced.** A signature prints as the typed name. The `stamp` child below is\nread-only legacy and must never be produced; its absence carries no meaning about validity."
      },
      {
        "id": "Extension.extension",
        "path": "Extension.extension",
        "min": 2
      },
      {
        "id": "Extension.extension:signer",
        "path": "Extension.extension",
        "sliceName": "signer",
        "short": "Who signed -- the ordering clinician, as a PractitionerRole where one resolved",
        "definition": "The clinician who signed the requisition. A `PractitionerRole` where the signing context resolved one, otherwise the `Practitioner`. `display` carries the name exactly as it printed on the signed sheet and is stored so a reprint does not change when the practitioner record does.",
        "min": 1,
        "max": "1",
        "mustSupport": true
      },
      {
        "id": "Extension.extension:signer.extension",
        "path": "Extension.extension.extension",
        "max": "0"
      },
      {
        "id": "Extension.extension:signer.url",
        "path": "Extension.extension.url",
        "fixedUri": "signer"
      },
      {
        "id": "Extension.extension:signer.value[x]",
        "path": "Extension.extension.value[x]",
        "type": [
          {
            "code": "Reference",
            "targetProfile": [
              "http://hl7.org/fhir/StructureDefinition/Practitioner",
              "http://hl7.org/fhir/StructureDefinition/PractitionerRole"
            ]
          }
        ]
      },
      {
        "id": "Extension.extension:signedAt",
        "path": "Extension.extension",
        "sliceName": "signedAt",
        "short": "When the requisition was signed -- a fully-qualified instant",
        "definition": "The moment the requisition was signed, as a timezone-qualified dateTime. This is the time of the signing write, which is not the same as `ServiceRequest.authoredOn`: authoring is preserved across an amendment while the signature is stamped afresh, so the two differ on any requisition that has been edited.",
        "min": 1,
        "max": "1",
        "mustSupport": true
      },
      {
        "id": "Extension.extension:signedAt.extension",
        "path": "Extension.extension.extension",
        "max": "0"
      },
      {
        "id": "Extension.extension:signedAt.url",
        "path": "Extension.extension.url",
        "fixedUri": "signedAt"
      },
      {
        "id": "Extension.extension:signedAt.value[x]",
        "path": "Extension.extension.value[x]",
        "type": [
          {
            "code": "dateTime"
          }
        ]
      },
      {
        "id": "Extension.extension:stamp",
        "path": "Extension.extension",
        "sliceName": "stamp",
        "short": "LEGACY, read-only: identifier of a stored signature-stamp document",
        "definition": "The identifier of a stored document holding the signer's stamp image, as captured at sign time. **Deprecated: no producer writes this, and none should.** It is described because requisitions signed under an earlier shape still carry it and must keep rebuilding exactly as they did. Its absence says nothing about the validity of a signature -- an unstamped signature prints as the typed name and is fully valid.",
        "min": 0,
        "max": "1"
      },
      {
        "id": "Extension.extension:stamp.extension",
        "path": "Extension.extension.extension",
        "max": "0"
      },
      {
        "id": "Extension.extension:stamp.url",
        "path": "Extension.extension.url",
        "fixedUri": "stamp"
      },
      {
        "id": "Extension.extension:stamp.value[x]",
        "path": "Extension.extension.value[x]",
        "type": [
          {
            "code": "string"
          }
        ]
      },
      {
        "id": "Extension.url",
        "path": "Extension.url",
        "fixedUri": "https://fhir.apps.health/StructureDefinition/nexus-requisition-signature"
      },
      {
        "id": "Extension.value[x]",
        "path": "Extension.value[x]",
        "max": "0"
      }
    ]
  }
}