EPSG:6927 - SVY21 / Singapore TM + SHD height

{
  "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
  "type": "CompoundCRS",
  "name": "SVY21 / Singapore TM + SHD height",
  "components": [
    {
      "type": "ProjectedCRS",
      "name": "SVY21 / Singapore TM",
      "base_crs": {
        "name": "SVY21",
        "datum": {
          "type": "GeodeticReferenceFrame",
          "name": "SVY21",
          "ellipsoid": {
            "name": "WGS 84",
            "semi_major_axis": 6378137,
            "inverse_flattening": 298.257223563
          }
        },
        "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": 4757
        }
      },
      "conversion": {
        "name": "Singapore Transverse Mercator",
        "method": {
          "name": "Transverse Mercator",
          "id": {
            "authority": "EPSG",
            "code": 9807
          }
        },
        "parameters": [
          {
            "name": "Latitude of natural origin",
            "value": 1.36666666666667,
            "unit": "degree",
            "id": {
              "authority": "EPSG",
              "code": 8801
            }
          },
          {
            "name": "Longitude of natural origin",
            "value": 103.833333333333,
            "unit": "degree",
            "id": {
              "authority": "EPSG",
              "code": 8802
            }
          },
          {
            "name": "Scale factor at natural origin",
            "value": 1,
            "unit": "unity",
            "id": {
              "authority": "EPSG",
              "code": 8805
            }
          },
          {
            "name": "False easting",
            "value": 28001.642,
            "unit": "metre",
            "id": {
              "authority": "EPSG",
              "code": 8806
            }
          },
          {
            "name": "False northing",
            "value": 38744.572,
            "unit": "metre",
            "id": {
              "authority": "EPSG",
              "code": 8807
            }
          }
        ]
      },
      "coordinate_system": {
        "subtype": "Cartesian",
        "axis": [
          {
            "name": "Northing",
            "abbreviation": "N",
            "direction": "north",
            "unit": "metre"
          },
          {
            "name": "Easting",
            "abbreviation": "E",
            "direction": "east",
            "unit": "metre"
          }
        ]
      }
    },
    {
      "type": "VerticalCRS",
      "name": "SHD height",
      "datum": {
        "type": "VerticalReferenceFrame",
        "name": "Singapore Height Datum"
      },
      "coordinate_system": {
        "subtype": "vertical",
        "axis": [
          {
            "name": "Gravity-related height",
            "abbreviation": "H",
            "direction": "up",
            "unit": "metre"
          }
        ]
      }
    }
  ],
  "scope": "Engineering survey, GIS, topographic mapping.",
  "area": "Singapore - onshore and offshore.",
  "bbox": {
    "south_latitude": 1.13,
    "west_longitude": 103.59,
    "north_latitude": 1.47,
    "east_longitude": 104.07
  },
  "id": {
    "authority": "EPSG",
    "code": 6927
  }
}

{'crs_wkt': 'COMPOUNDCRS["SVY21 / Singapore TM + SHD height",PROJCRS["SVY21 / '
            'Singapore TM",BASEGEOGCRS["SVY21",DATUM["SVY21",ELLIPSOID["WGS '
            '84",6378137,298.257223563,LENGTHUNIT["metre",1]]],PRIMEM["Greenwich",0,ANGLEUNIT["degree",0.0174532925199433]],ID["EPSG",4757]],CONVERSION["Singapore '
            'Transverse Mercator",METHOD["Transverse '
            'Mercator",ID["EPSG",9807]],PARAMETER["Latitude of natural '
            'origin",1.36666666666667,ANGLEUNIT["degree",0.0174532925199433],ID["EPSG",8801]],PARAMETER["Longitude '
            'of natural '
            'origin",103.833333333333,ANGLEUNIT["degree",0.0174532925199433],ID["EPSG",8802]],PARAMETER["Scale '
            'factor at natural '
            'origin",1,SCALEUNIT["unity",1],ID["EPSG",8805]],PARAMETER["False '
            'easting",28001.642,LENGTHUNIT["metre",1],ID["EPSG",8806]],PARAMETER["False '
            'northing",38744.572,LENGTHUNIT["metre",1],ID["EPSG",8807]]],CS[Cartesian,2],AXIS["northing '
            '(N)",north,ORDER[1],LENGTHUNIT["metre",1]],AXIS["easting '
            '(E)",east,ORDER[2],LENGTHUNIT["metre",1]]],VERTCRS["SHD '
            'height",VDATUM["Singapore Height '
            'Datum"],CS[vertical,1],AXIS["gravity-related height '
            '(H)",up,LENGTHUNIT["metre",1]]],USAGE[SCOPE["Engineering survey, '
            'GIS, topographic mapping."],AREA["Singapore - onshore and '
            'offshore."],BBOX[1.13,103.59,1.47,104.07]],ID["EPSG",6927]]',
 'false_easting': 28001.642,
 'false_northing': 38744.572,
 'geographic_crs_name': 'SVY21',
 'geopotential_datum_name': 'Singapore Height Datum',
 'grid_mapping_name': 'transverse_mercator',
 'horizontal_datum_name': 'SVY21',
 'inverse_flattening': 298.257223563,
 'latitude_of_projection_origin': 1.36666666666667,
 'longitude_of_central_meridian': 103.833333333333,
 'longitude_of_prime_meridian': 0.0,
 'prime_meridian_name': 'Greenwich',
 'projected_crs_name': 'SVY21 / Singapore TM',
 'reference_ellipsoid_name': 'WGS 84',
 'scale_factor_at_central_meridian': 1.0,
 'semi_major_axis': 6378137.0,
 'semi_minor_axis': 6356752.314245179}