Xrail84 3D - EPSG:10992

WKT

GEOGCS["Xrail84_3D", 
	DATUM["D_Xrail84", 
		SPHEROID["WGS_1984", 6378137.0, 298.257223563]], 
	PRIMEM["Greenwich", 0.0], 
	UNIT["Degree", 0.0174532925199433], 
	LINUNIT["Meter", 1.0]]

WKT2

GEOGCRS["Xrail84_3D", 
	DATUM["D_Xrail84", 
		ELLIPSOID["WGS_1984", 6378137.0, 298.257223563]], 
	PRIMEM["Greenwich", 0.0], 
	CS[ellipsoidal, 3], 
	AXIS["Latitude (lat)", north, 
		ORDER[1], 
		ANGLEUNIT["Degree", 0.0174532925199433]], 
	AXIS["Longitude (lon)", east, 
		ORDER[2], 
		ANGLEUNIT["Degree", 0.0174532925199433]], 
	AXIS["Ellipsoidal height (h)", up, 
		ORDER[3], 
		LENGTHUNIT["Meter", 1.0]], 
	ID["EPSG", "10992"]]

Data from @esri/proj-codes

{
  "wkid": 10992,
  "latestWkid": 10992,
  "macro": "PE_GCS_XRAIL84_3D",
  "name": "Xrail84_3D",
  "wkt": "GEOGCS[\"Xrail84_3D\",DATUM[\"D_Xrail84\",SPHEROID[\"WGS_1984\",6378137.0,298.257223563]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433],LINUNIT[\"Meter\",1.0]]",
  "wkt2": "GEOGCRS[\"Xrail84_3D\",DATUM[\"D_Xrail84\",ELLIPSOID[\"WGS_1984\",6378137.0,298.257223563]],PRIMEM[\"Greenwich\",0.0],CS[ellipsoidal,3],AXIS[\"Latitude (lat)\",north,ORDER[1],ANGLEUNIT[\"Degree\",0.0174532925199433]],AXIS[\"Longitude (lon)\",east,ORDER[2],ANGLEUNIT[\"Degree\",0.0174532925199433]],AXIS[\"Ellipsoidal height (h)\",up,ORDER[3],LENGTHUNIT[\"Meter\",1.0]],ID[\"EPSG\",\"10992\"]]",
  "description": "Xrail84 3D",
  "authority": "EPSG",
  "version": "12.031(13.7.0)",
  "deprecated": "no",
  "extent": [
    {
      "areaname": "UK - Greater London",
      "slat": 51.1,
      "nlat": 52,
      "llon": -1.33,
      "rlon": 0.8
    }
  ]
}