EPSG:3950 - RGF93 v1 / CC50

{
  "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
  "type": "ProjectedCRS",
  "name": "RGF93 v1 / CC50",
  "base_crs": {
    "name": "RGF93 v1",
    "datum": {
      "type": "GeodeticReferenceFrame",
      "name": "Reseau Geodesique Francais 1993 v1",
      "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"
        }
      ]
    },
    "id": {
      "authority": "EPSG",
      "code": 4171
    }
  },
  "conversion": {
    "name": "France Conic Conformal zone 9",
    "method": {
      "name": "Lambert Conic Conformal (2SP)",
      "id": {
        "authority": "EPSG",
        "code": 9802
      }
    },
    "parameters": [
      {
        "name": "Latitude of false origin",
        "value": 50,
        "unit": "degree",
        "id": {
          "authority": "EPSG",
          "code": 8821
        }
      },
      {
        "name": "Longitude of false origin",
        "value": 3,
        "unit": "degree",
        "id": {
          "authority": "EPSG",
          "code": 8822
        }
      },
      {
        "name": "Latitude of 1st standard parallel",
        "value": 49.25,
        "unit": "degree",
        "id": {
          "authority": "EPSG",
          "code": 8823
        }
      },
      {
        "name": "Latitude of 2nd standard parallel",
        "value": 50.75,
        "unit": "degree",
        "id": {
          "authority": "EPSG",
          "code": 8824
        }
      },
      {
        "name": "Easting at false origin",
        "value": 1700000,
        "unit": "metre",
        "id": {
          "authority": "EPSG",
          "code": 8826
        }
      },
      {
        "name": "Northing at false origin",
        "value": 9200000,
        "unit": "metre",
        "id": {
          "authority": "EPSG",
          "code": 8827
        }
      }
    ]
  },
  "coordinate_system": {
    "subtype": "Cartesian",
    "axis": [
      {
        "name": "Easting",
        "abbreviation": "X",
        "direction": "east",
        "unit": "metre"
      },
      {
        "name": "Northing",
        "abbreviation": "Y",
        "direction": "north",
        "unit": "metre"
      }
    ]
  },
  "scope": "Cadastre, engineering survey.",
  "area": "France - mainland onshore north of 49°N.",
  "bbox": {
    "south_latitude": 49,
    "west_longitude": -2.03,
    "north_latitude": 51.14,
    "east_longitude": 8.08
  },
  "id": {
    "authority": "EPSG",
    "code": 3950
  }
}

{'crs_wkt': 'PROJCRS["RGF93 v1 / CC50",BASEGEOGCRS["RGF93 v1",DATUM["Reseau '
            'Geodesique Francais 1993 v1",ELLIPSOID["GRS '
            '1980",6378137,298.257222101,LENGTHUNIT["metre",1]]],PRIMEM["Greenwich",0,ANGLEUNIT["degree",0.0174532925199433]],ID["EPSG",4171]],CONVERSION["France '
            'Conic Conformal zone 9",METHOD["Lambert Conic Conformal '
            '(2SP)",ID["EPSG",9802]],PARAMETER["Latitude of false '
            'origin",50,ANGLEUNIT["degree",0.0174532925199433],ID["EPSG",8821]],PARAMETER["Longitude '
            'of false '
            'origin",3,ANGLEUNIT["degree",0.0174532925199433],ID["EPSG",8822]],PARAMETER["Latitude '
            'of 1st standard '
            'parallel",49.25,ANGLEUNIT["degree",0.0174532925199433],ID["EPSG",8823]],PARAMETER["Latitude '
            'of 2nd standard '
            'parallel",50.75,ANGLEUNIT["degree",0.0174532925199433],ID["EPSG",8824]],PARAMETER["Easting '
            'at false '
            'origin",1700000,LENGTHUNIT["metre",1],ID["EPSG",8826]],PARAMETER["Northing '
            'at false '
            'origin",9200000,LENGTHUNIT["metre",1],ID["EPSG",8827]]],CS[Cartesian,2],AXIS["easting '
            '(X)",east,ORDER[1],LENGTHUNIT["metre",1]],AXIS["northing '
            '(Y)",north,ORDER[2],LENGTHUNIT["metre",1]],USAGE[SCOPE["Cadastre, '
            'engineering survey."],AREA["France - mainland onshore north of '
            '49°N."],BBOX[49,-2.03,51.14,8.08]],ID["EPSG",3950]]',
 'false_easting': 1700000.0,
 'false_northing': 9200000.0,
 'geographic_crs_name': 'RGF93 v1',
 'grid_mapping_name': 'lambert_conformal_conic',
 'horizontal_datum_name': 'Reseau Geodesique Francais 1993 v1',
 'inverse_flattening': 298.257222101,
 'latitude_of_projection_origin': 50.0,
 'longitude_of_central_meridian': 3.0,
 'longitude_of_prime_meridian': 0.0,
 'prime_meridian_name': 'Greenwich',
 'projected_crs_name': 'RGF93 v1 / CC50',
 'reference_ellipsoid_name': 'GRS 1980',
 'semi_major_axis': 6378137.0,
 'semi_minor_axis': 6356752.314140356,
 'standard_parallel': (49.25, 50.75)}