EPSG:5748 — Flannan Isles height

VERTCRS[
    "Flannan Isles height",
    VDATUM["Flannan Isles",ID["EPSG",5146]],
    CS[vertical,1,ID["EPSG",6499]],
    AXIS["Gravity-related height (H)",up],
    LENGTHUNIT["metre",1,ID["EPSG",9001]],
    GEOIDMODEL["ETRS89 to Flannan Isles height (1)",ID["EPSG",10025]],
    ID["EPSG",5748]
]

+vunits=m +no_defs +type=crs

proj4.defs("EPSG:5748", "+vunits=m +no_defs +type=crs");

{
  "type": "CoordinateReferenceSystem",
  "code": 5748,
  "name": "Flannan Isles height",
  "kind": "vertical",
  "area": "UK - Flannan Isles onshore",
  "unit": "metre",
  "bbox": [
    58.21,
    -7.75,
    58.35,
    -7.46
  ],
  "proj4": "+vunits=m +no_defs +type=crs"
}

INSERT INTO spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext)
VALUES (5748, 'EPSG', 5748, '+vunits=m +no_defs +type=crs', 'VERT_CS["Flannan Isles height",VERT_DATUM["Flannan Isles",2005,AUTHORITY["EPSG","5146"]],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Gravity-related height",UP],AUTHORITY["EPSG","5748"]]');

PROJECTION
  "+vunits=m"
  "+no_defs"
  "+type=crs"
END

5748=VERT_CS["Flannan Isles height",VERT_DATUM["Flannan Isles",2005,AUTHORITY["EPSG","5146"]],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Gravity-related height",UP],AUTHORITY["EPSG","5748"]]