EPSG:7956 — SHMG2015 + SHVD2015 height

COMPOUNDCRS[
    "SHMG2015 + SHVD2015 height",
    PROJCRS[
        "SHMG2015",
        BASEGEOGCRS[
            "SHGD2015",
            DATUM[
                "St. Helena Geodetic Datum 2015",
                ELLIPSOID[
                    "GRS 1980",
                    6378137,
                    298.257222101,
                    LENGTHUNIT["metre",1,ID["EPSG",9001]],
                    ID["EPSG",7019]
                ],
                ID["EPSG",1174]
            ],
            ID["EPSG",7886]
        ],
        CONVERSION[
            "UTM zone 30S",
            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",
                -3,
                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",16130]
        ],
        CS[Cartesian,2,ID["EPSG",4400]],
        AXIS["Easting (E)",east],
        AXIS["Northing (N)",north],
        LENGTHUNIT["metre",1,ID["EPSG",9001]],
        ID["EPSG",7887]
    ],
    VERTCRS[
        "SHVD2015 height",
        VDATUM["St. Helena Vertical Datum 2015",ID["EPSG",1177]],
        CS[vertical,1,ID["EPSG",6499]],
        AXIS["Gravity-related height (H)",up],
        LENGTHUNIT["metre",1,ID["EPSG",9001]],
        GEOIDMODEL["SHGD2015 to SHVD2015 height (1)",ID["EPSG",7891]],
        ID["EPSG",7890]
    ],
    ID["EPSG",7956]
]

+proj=utm +zone=30 +south +ellps=GRS80 +units=m +vunits=m +no_defs +type=crs

proj4.defs("EPSG:7956", "+proj=utm +zone=30 +south +ellps=GRS80 +units=m +vunits=m +no_defs +type=crs");

{
  "type": "CoordinateReferenceSystem",
  "code": 7956,
  "name": "SHMG2015 + SHVD2015 height",
  "kind": "compound",
  "area": "St Helena - St Helena Island",
  "unit": null,
  "bbox": [
    -16.08,
    -5.85,
    -15.85,
    -5.59
  ],
  "proj4": "+proj=utm +zone=30 +south +ellps=GRS80 +units=m +vunits=m +no_defs +type=crs"
}

INSERT INTO spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext)
VALUES (7956, 'EPSG', 7956, '+proj=utm +zone=30 +south +ellps=GRS80 +units=m +vunits=m +no_defs +type=crs', 'COMPD_CS["SHMG2015 + SHVD2015 height",PROJCS["SHMG2015",GEOGCS["SHGD2015",DATUM["St_Helena_Geodetic_Datum_2015",SPHEROID["GRS 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","1174"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","7886"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",-3],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","7887"]],VERT_CS["SHVD2015 height",VERT_DATUM["St. Helena Vertical Datum 2015",2005,AUTHORITY["EPSG","1177"]],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Gravity-related height",UP],AUTHORITY["EPSG","7890"]],AUTHORITY["EPSG","7956"]]');

PROJECTION
  "+proj=utm"
  "+zone=30"
  "+south"
  "+ellps=GRS80"
  "+units=m"
  "+vunits=m"
  "+no_defs"
  "+type=crs"
END

7956=COMPD_CS["SHMG2015 + SHVD2015 height",PROJCS["SHMG2015",GEOGCS["SHGD2015",DATUM["St_Helena_Geodetic_Datum_2015",SPHEROID["GRS 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","1174"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","7886"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",-3],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","7887"]],VERT_CS["SHVD2015 height",VERT_DATUM["St. Helena Vertical Datum 2015",2005,AUTHORITY["EPSG","1177"]],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Gravity-related height",UP],AUTHORITY["EPSG","7890"]],AUTHORITY["EPSG","7956"]]