http://hl7.org/fhir/StructureDefinition/characteristicExpression|5.2.0

{
  "description": "An expression that defines the criteria for group membership. This extension can only be used on a Group resource with a membership of `definitional`. When this expression is used, the Group resource cannot have any characteristic elements; this mechanism is exclusive with characteristics. The result of the expression SHALL be boolean-valued. The expression SHALL be parameterized with a `%context` variable that represents the subject being tested for membership. If evaluation of the expression results in `true`, the subject is considered a member of the group.",
  "package": "hl7.fhir.uv.extensions.r4@5.2.0",
  "date": "2013-12-05T00:00:00Z",
  "derivation": "constraint",
  "publisher": "HL7 International / FHIR Infrastructure",
  "fhirVersion": "4.0.1",
  "jurisdiction": [ {
    "coding": [ {
      "code": "001",
      "system": "http://unstats.un.org/unsd/methods/m49/m49.htm"
    } ]
  } ],
  "name": "CharacteristicExpression",
  "mapping": [ {
    "uri": "http://hl7.org/v3",
    "name": "RIM Mapping",
    "identity": "rim"
  } ],
  "abstract": false,
  "type": "Extension",
  "experimental": false,
  "resourceType": "StructureDefinition",
  "fhirversion": null,
  "title": "Characteristic Expression",
  "versionAlgorithmCoding": null,
  "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"
  }, {
    "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-type-characteristics",
    "valueCode": "can-bind"
  } ],
  "status": "draft",
  "id": "03d34bfa-7cc3-5210-98b8-4869b2b0dcce",
  "kind": "complex-type",
  "url": "http://hl7.org/fhir/StructureDefinition/characteristicExpression",
  "identifier": [ {
    "value": "urn:oid:2.16.840.1.113883.4.642.5.1557",
    "system": "urn:ietf:rfc:3986"
  } ],
  "context": [ {
    "type": "element",
    "expression": "Group"
  } ],
  "versionAlgorithmString": null,
  "fhir_id": null,
  "version": "5.2.0",
  "contact": [ {
    "telecom": [ {
      "value": "http://www.hl7.org/Special/committees/fiwg",
      "system": "url"
    } ]
  } ],
  "baseDefinition": "http://hl7.org/fhir/StructureDefinition/Extension"
}