EPSG:9517 - SHGD2015 + SHVD2015 height

{
  "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
  "type": "CompoundCRS",
  "name": "SHGD2015 + SHVD2015 height",
  "components": [
    {
      "type": "GeographicCRS",
      "name": "SHGD2015",
      "datum": {
        "type": "GeodeticReferenceFrame",
        "name": "St. Helena Geodetic Datum 2015",
        "ellipsoid": {
          "name": "GRS 1980",
          "semi_major_axis": 6378137,
          "inverse_flattening": 298.257222101
        }
      },
      "coordinate_system": {
        "subtype": "ellipsoidal",
        "axis": [
          {
            "name": "Geodetic latitude",
            "abbreviation": "Lat",
            "direction": "north",
            "unit": "degree"
          },
          {
            "name": "Geodetic longitude",
            "abbreviation": "Lon",
            "direction": "east",
            "unit": "degree"
          }
        ]
      }
    },
    {
      "type": "VerticalCRS",
      "name": "SHVD2015 height",
      "datum": {
        "type": "VerticalReferenceFrame",
        "name": "St. Helena Vertical Datum 2015"
      },
      "coordinate_system": {
        "subtype": "vertical",
        "axis": [
          {
            "name": "Gravity-related height",
            "abbreviation": "H",
            "direction": "up",
            "unit": "metre"
          }
        ]
      }
    }
  ],
  "scope": "Spatial referencing.",
  "area": "St Helena, Ascension and Tristan da Cunha - St Helena Island - onshore.",
  "bbox": {
    "south_latitude": -16.08,
    "west_longitude": -5.85,
    "north_latitude": -15.85,
    "east_longitude": -5.59
  },
  "id": {
    "authority": "EPSG",
    "code": 9517
  }
}

{'crs_wkt': 'COMPOUNDCRS["SHGD2015 + SHVD2015 '
            'height",GEOGCRS["SHGD2015",DATUM["St. Helena Geodetic Datum '
            '2015",ELLIPSOID["GRS '
            '1980",6378137,298.257222101,LENGTHUNIT["metre",1]]],PRIMEM["Greenwich",0,ANGLEUNIT["degree",0.0174532925199433]],CS[ellipsoidal,2],AXIS["geodetic '
            'latitude '
            '(Lat)",north,ORDER[1],ANGLEUNIT["degree",0.0174532925199433]],AXIS["geodetic '
            'longitude '
            '(Lon)",east,ORDER[2],ANGLEUNIT["degree",0.0174532925199433]]],VERTCRS["SHVD2015 '
            'height",VDATUM["St. Helena Vertical Datum '
            '2015"],CS[vertical,1],AXIS["gravity-related height '
            '(H)",up,LENGTHUNIT["metre",1]]],USAGE[SCOPE["Spatial '
            'referencing."],AREA["St Helena, Ascension and Tristan da Cunha - '
            'St Helena Island - '
            'onshore."],BBOX[-16.08,-5.85,-15.85,-5.59]],ID["EPSG",9517]]',
 'geographic_crs_name': 'SHGD2015',
 'geopotential_datum_name': 'St. Helena Vertical Datum 2015',
 'grid_mapping_name': 'latitude_longitude',
 'horizontal_datum_name': 'St. Helena Geodetic Datum 2015',
 'inverse_flattening': 298.257222101,
 'longitude_of_prime_meridian': 0.0,
 'prime_meridian_name': 'Greenwich',
 'reference_ellipsoid_name': 'GRS 1980',
 'semi_major_axis': 6378137.0,
 'semi_minor_axis': 6356752.314140356}