EPSG:9540

COMPD_CS["RGNC91-93 + NGNC08 height",
    GEOGCS["RGNC91-93",
        DATUM["Reseau_Geodesique_de_Nouvelle_Caledonie_91-93",
            SPHEROID["GRS 1980",6378137,298.257222101,
                AUTHORITY["EPSG","7019"]],
            AUTHORITY["EPSG","6749"]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9122"]],
        AUTHORITY["EPSG","4749"]],
    VERT_CS["NGNC08 height",
        VERT_DATUM["Nivellement General de Nouvelle Caledonie 2008",2005,
            AUTHORITY["EPSG","1255"]],
        UNIT["metre",1,
            AUTHORITY["EPSG","9001"]],
        AXIS["Gravity-related height",UP],
        AUTHORITY["EPSG","9351"]],
    AUTHORITY["EPSG","9540"]]

COMPOUNDCRS["RGNC91-93 + NGNC08 height",
    GEOGCRS["RGNC91-93",
        DATUM["Reseau Geodesique de Nouvelle Caledonie 91-93",
            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["NGNC08 height",
        VDATUM["Nivellement General de Nouvelle Caledonie 2008"],
        CS[vertical,1],
            AXIS["gravity-related height (H)",up,
                LENGTHUNIT["metre",1]]],
    USAGE[
        SCOPE["Spatial referencing."],
        AREA["New Caledonia - Belep, Grande Terre, Ile des Pins, Loyalty Islands (Lifou, Mare, Ouvea)."],
        BBOX[-22.73,163.54,-19.5,168.19]],
    ID["EPSG",9540]]

GEOGCS["GCS_RGNC_1991-93",
    DATUM["D_Reseau_Geodesique_de_Nouvelle_Caledonie_1991-93",
        SPHEROID["GRS_1980",6378137.0,298.257222101]],
    PRIMEM["Greenwich",0.0],
    UNIT["Degree",0.0174532925199433]],
VERTCS["NGNC08_height",
    VDATUM["Nivellement_General_de_Nouvelle_Caledonie_2008"],
    PARAMETER["Vertical_Shift",0.0],
    PARAMETER["Direction",1.0],
    UNIT["Meter",1.0]]

proj4.defs("EPSG:9540","+proj=longlat +ellps=GRS80 +vunits=m +no_defs +type=crs");

{
    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
    "type": "CompoundCRS",
    "name": "RGNC91-93 + NGNC08 height",
    "components": [
        {
            "type": "GeographicCRS",
            "name": "RGNC91-93",
            "datum": {
                "type": "GeodeticReferenceFrame",
                "name": "Reseau Geodesique de Nouvelle Caledonie 91-93",
                "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": "NGNC08 height",
            "datum": {
                "type": "VerticalReferenceFrame",
                "name": "Nivellement General de Nouvelle Caledonie 2008"
            },
            "coordinate_system": {
                "subtype": "vertical",
                "axis": [
                    {
                        "name": "Gravity-related height",
                        "abbreviation": "H",
                        "direction": "up",
                        "unit": "metre"
                    }
                ]
            }
        }
    ],
    "scope": "Spatial referencing.",
    "area": "New Caledonia - Belep, Grande Terre, Ile des Pins, Loyalty Islands (Lifou, Mare, Ouvea).",
    "bbox": {
        "south_latitude": -22.73,
        "west_longitude": 163.54,
        "north_latitude": -19.5,
        "east_longitude": 168.19
    },
    "id": {
        "authority": "EPSG",
        "code": 9540
    }
}

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=longlat +ellps=GRS80 +vunits=m +no_defs +type=crs">
	<Layer srs="+proj=longlat +ellps=GRS80 +vunits=m +no_defs +type=crs">
	</Layer>
</Map>

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 9540, 'EPSG', 9540, '+proj=longlat +ellps=GRS80 +vunits=m +no_defs +type=crs', 'COMPD_CS["RGNC91-93 + NGNC08 height",GEOGCS["RGNC91-93",DATUM["Reseau_Geodesique_de_Nouvelle_Caledonie_91-93",SPHEROID["GRS 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","6749"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4749"]],VERT_CS["NGNC08 height",VERT_DATUM["Nivellement General de Nouvelle Caledonie 2008",2005,AUTHORITY["EPSG","1255"]],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Gravity-related height",UP],AUTHORITY["EPSG","9351"]],AUTHORITY["EPSG","9540"]]');