{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://schema.govfresh.com/v1/_core/geometry.schema.json",
  "title": "Geometry",
  "description": "A shape on the earth, held either by reference or inline.",
  "type": "object",
  "properties": {
    "@type": {"const": "Geometry", "description": "Always `Geometry` - a value type rather than an entity, like `Identifier` and `MonetaryAmount`. `schema:GeoShape` cannot do this job: its polygon is a space-delimited text string with no coordinate reference system, no multipolygon and no interior rings, and schema.org's own `GeospatialGeometry` is a declared placeholder that was never filled in. Exactly one of `contentUrl` or `coordinates` must be present."},
    "geometryType": {
      "type": "string",
      "description": "GeoJSON geometry type. MultiPolygon is the common case for real administrative areas, which have islands and exclaves.",
      "enum": ["Point", "LineString", "Polygon", "MultiPoint", "MultiLineString", "MultiPolygon", "GeometryCollection"]
    },
    "contentUrl": {
      "type": "string", "format": "iri",
      "description": "URL of a GeoJSON resource. The default for anything shared, authoritative or large: a jurisdiction boundary is referenced by every record in that jurisdiction, and duplicating it into each is the drift SPEC section 1.2 exists to prevent."
    },
    "coordinates": {
      "description": "Inline GeoJSON coordinates. Permitted for geometry that is specific to one record and small - an alert polygon, a parcel outline - because real standards inline it and a profile that forbade it could not describe CAP. The validator warns above a vertex threshold rather than failing, since that is a publishing judgement rather than a correctness error.",
      "type": "array"
    },
    "encodingFormat": {"type": "string", "description": "Usually application/geo+json."},
    "sourceReferenceSystem": {
      "type": "string",
      "description": "The CRS the publisher's authoritative source is held in, as an OGC CRS URI or 'epsg:NNNN' shorthand. This is provenance, not a claim about the coordinates here: GeoJSON mandates WGS84 longitude/latitude and forbids alternatives, so referenced and inline GeoJSON are always CRS84. Recording it matters because national-grid coordinates read as WGS84 land in the wrong hemisphere."
    },
    "simplified": {
      "type": "boolean",
      "description": "Whether this is a generalised rendering for display. A simplified boundary is not the legal boundary, and using one to decide whether an address falls inside a district gives wrong answers at the edges. A consumer needs to know which it has."
    },
    "vertexCount": {"type": "integer", "minimum": 0, "description": "Approximate vertex count, where the publisher knows it."}
  },
  "required": ["@type", "geometryType"],
  "oneOf": [
    {"required": ["contentUrl"], "not": {"required": ["coordinates"]}},
    {"required": ["coordinates"], "not": {"required": ["contentUrl"]}}
  ],
  "additionalProperties": false
}