{
  "resourceType": "StructureDefinition",
  "id": "city-gnis-code",
  "url": "https://emsinterop.com/fhir/StructureDefinition/ems-city-gnis-code",
  "version": "0.1.0",
  "name": "CityGnisCode",
  "title": "City GNIS Feature Id",
  "status": "draft",
  "description": "The USGS GNIS feature id NEMSIS stores for a city (CityGnisCode: ePatient.06, eScene.17, eDisposition.04, dContact.06, dPersonnel.05). FHIR's Address.city is \"Name of city, town etc.\" and R4 Address has no coded-place element, so writing the id there would misrepresent a code as a name \u2014 a receiving system displays it verbatim, and a clinician reads \"1454997\" as the town. The name is populated only when a gazetteer resolves it; this extension carries the id so the NEMSIS round trip stays exact rather than the value being dropped. Retired if FHIR defines a coded-city representation.",
  "fhirVersion": "4.0.1",
  "kind": "complex-type",
  "abstract": false,
  "context": [
    {
      "type": "element",
      "expression": "Address"
    }
  ],
  "type": "Extension",
  "baseDefinition": "http://hl7.org/fhir/StructureDefinition/Extension",
  "derivation": "constraint",
  "differential": {
    "element": [
      {
        "id": "Extension",
        "path": "Extension",
        "short": "City GNIS feature id",
        "min": 0,
        "max": "1"
      },
      {
        "id": "Extension.extension",
        "path": "Extension.extension",
        "max": "0"
      },
      {
        "id": "Extension.url",
        "path": "Extension.url",
        "fixedUri": "https://emsinterop.com/fhir/StructureDefinition/ems-city-gnis-code"
      },
      {
        "id": "Extension.value[x]",
        "path": "Extension.value[x]",
        "min": 1,
        "max": "1",
        "type": [
          {
            "code": "string"
          }
        ]
      }
    ]
  },
  "identifier": [
    {
      "system": "urn:ietf:rfc:3986",
      "value": "urn:emsinterop:extension:city-gnis-code"
    }
  ]
}