EPSG:20356 — AGD84 / AMG zone 56

PROJCRS[
    "AGD84 / AMG zone 56",
    BASEGEOGCRS[
        "AGD84",
        DATUM[
            "Australian Geodetic Datum 1984",
            ELLIPSOID[
                "Australian National Spheroid",
                6378160,
                298.25,
                LENGTHUNIT["metre",1,ID["EPSG",9001]],
                ID["EPSG",7003]
            ],
            ID["EPSG",6203]
        ],
        ID["EPSG",4203]
    ],
    CONVERSION[
        "Australian Map Grid zone 56",
        METHOD["Transverse Mercator",ID["EPSG",9807]],
        PARAMETER[
            "Latitude of natural origin",
            0,
            ANGLEUNIT["degree",0.0174532925199433,ID["EPSG",9102]],
            ID["EPSG",8801]
        ],
        PARAMETER[
            "Longitude of natural origin",
            153,
            ANGLEUNIT["degree",0.0174532925199433,ID["EPSG",9102]],
            ID["EPSG",8802]
        ],
        PARAMETER[
            "Scale factor at natural origin",
            0.9996,
            SCALEUNIT["unity",1,ID["EPSG",9201]],
            ID["EPSG",8805]
        ],
        PARAMETER[
            "False easting",
            500000,
            LENGTHUNIT["metre",1,ID["EPSG",9001]],
            ID["EPSG",8806]
        ],
        PARAMETER[
            "False northing",
            10000000,
            LENGTHUNIT["metre",1,ID["EPSG",9001]],
            ID["EPSG",8807]
        ],
        ID["EPSG",17456]
    ],
    CS[Cartesian,2,ID["EPSG",4400]],
    AXIS["Easting (E)",east],
    AXIS["Northing (N)",north],
    LENGTHUNIT["metre",1,ID["EPSG",9001]],
    ID["EPSG",20356]
]

+proj=utm +zone=56 +south +ellps=aust_SA +nadgrids="National 84 (02.07.01).gsb" +units=m +no_defs +type=crs

proj4.defs("EPSG:20356", "+proj=utm +zone=56 +south +ellps=aust_SA +nadgrids="National 84 (02.07.01).gsb" +units=m +no_defs +type=crs");

{
  "type": "CoordinateReferenceSystem",
  "code": 20356,
  "name": "AGD84 / AMG zone 56",
  "kind": "projected",
  "area": "Australia - Qld east of 150°E",
  "unit": "metre",
  "bbox": [
    -29.19,
    150,
    -22,
    153.61
  ],
  "proj4": "+proj=utm +zone=56 +south +ellps=aust_SA +nadgrids=\"National 84 (02.07.01).gsb\" +units=m +no_defs +type=crs"
}

INSERT INTO spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext)
VALUES (20356, 'EPSG', 20356, '+proj=utm +zone=56 +south +ellps=aust_SA +nadgrids="National 84 (02.07.01).gsb" +units=m +no_defs +type=crs', 'PROJCS["AGD84 / AMG zone 56",GEOGCS["AGD84",DATUM["Australian_Geodetic_Datum_1984",SPHEROID["Australian National Spheroid",6378160,298.25],EXTENSION["PROJ4_GRIDS","National 84 (02.07.01).gsb"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4203"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",153],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",10000000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","20356"]]');

PROJECTION
  "+proj=utm"
  "+zone=56"
  "+south"
  "+ellps=aust_SA"
  "+nadgrids="National"
  "84"
  "(02.07.01).gsb""
  "+units=m"
  "+no_defs"
  "+type=crs"
END

20356=PROJCS["AGD84 / AMG zone 56",GEOGCS["AGD84",DATUM["Australian_Geodetic_Datum_1984",SPHEROID["Australian National Spheroid",6378160,298.25],EXTENSION["PROJ4_GRIDS","National 84 (02.07.01).gsb"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4203"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",153],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",10000000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","20356"]]