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 — 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.
| Canonical | https://emsinterop.com/fhir/StructureDefinition/ems-city-gnis-code |
|---|---|
| Resource type | StructureDefinition |
| Version | 0.1.0 |
| Status | draft |
| Also identified by | urn:emsinterop:extension:city-gnis-code |
{
"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"
}
]
}