EPSG:1568

COORDINATEOPERATION["NZGD49 to NZGD2000 (3)",
    VERSION["OSG-Nzl 1m"],
    SOURCECRS[
        GEOGCRS["NZGD49",
            DATUM["New Zealand Geodetic Datum 1949",
                ELLIPSOID["International 1924",6378388,297,
                    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]],
            ID["EPSG",4272]]],
    TARGETCRS[
        GEOGCRS["NZGD2000",
            DATUM["New Zealand Geodetic Datum 2000",
                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]],
            ID["EPSG",4167]]],
    METHOD["NTv2",
        ID["EPSG",9615]],
    PARAMETERFILE["Latitude and longitude difference file","nzgd2kgrid0005.gsb"],
    OPERATIONACCURACY[0.2],
    USAGE[
        SCOPE["Transformation of coordinates at 0.2m level of accuracy."],
        AREA["New Zealand - North Island, South Island, Stewart Island - onshore and nearshore."],
        BBOX[-47.65,165.87,-33.89,179.27]],
    ID["EPSG",1568],
    REMARK["These same parameter values may be used to transform to WGS 84 - see NZGD49 to WGS 84 (4) (code 1670)."]]

proj4.defs("EPSG:1568","+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=hgridshift +grids=nz_linz_nzgd2kgrid0005.tif +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1");

{
    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
    "type": "Transformation",
    "name": "NZGD49 to NZGD2000 (3)",
    "source_crs": {
        "type": "GeographicCRS",
        "name": "NZGD49",
        "datum": {
            "type": "GeodeticReferenceFrame",
            "name": "New Zealand Geodetic Datum 1949",
            "ellipsoid": {
                "name": "International 1924",
                "semi_major_axis": 6378388,
                "inverse_flattening": 297
            }
        },
        "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": 4272
        }
    },
    "target_crs": {
        "type": "GeographicCRS",
        "name": "NZGD2000",
        "datum": {
            "type": "GeodeticReferenceFrame",
            "name": "New Zealand Geodetic Datum 2000",
            "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": 4167
        }
    },
    "method": {
        "name": "NTv2",
        "id": {
            "authority": "EPSG",
            "code": 9615
        }
    },
    "parameters": [
        {
            "name": "Latitude and longitude difference file",
            "value": "nzgd2kgrid0005.gsb",
            "id": {
                "authority": "EPSG",
                "code": 8656
            }
        }
    ],
    "accuracy": "0.2",
    "scope": "Transformation of coordinates at 0.2m level of accuracy.",
    "area": "New Zealand - North Island, South Island, Stewart Island - onshore and nearshore.",
    "bbox": {
        "south_latitude": -47.65,
        "west_longitude": 165.87,
        "north_latitude": -33.89,
        "east_longitude": 179.27
    },
    "id": {
        "authority": "EPSG",
        "code": 1568
    },
    "remarks": "These same parameter values may be used to transform to WGS 84 - see NZGD49 to WGS 84 (4) (code 1670)."
}

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=hgridshift +grids=nz_linz_nzgd2kgrid0005.tif +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1">
	<Layer srs="+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=hgridshift +grids=nz_linz_nzgd2kgrid0005.tif +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1">
	</Layer>
</Map>

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 1568, 'EPSG', 1568, '+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=hgridshift +grids=nz_linz_nzgd2kgrid0005.tif +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1', 'None');