CIGD11 + LCVD61 height (ft) - EPSG:9504

WKT

HVCOORDSYS["CIGD11_and_LCVD61_height_(ft)", 
	GEOGCS["GCS_CIGD11", 
		DATUM["D_Cayman_Islands_Geodetic_Datum_2011", 
			SPHEROID["GRS_1980", 6378137.0, 298.257222101]], 
		PRIMEM["Greenwich", 0.0], 
		UNIT["Degree", 0.0174532925199433]], 
	VERTCS["LCVD61_height", 
		VDATUM["Little_Cayman_Vertical_Datum_1961"], 
		PARAMETER["Vertical_Shift", 0.0], 
		PARAMETER["Direction", 1.0], 
		UNIT["Foot", 0.3048]]]

WKT2

COMPOUNDCRS["CIGD11_and_LCVD61_height_(ft)", 
	GEOGCRS["GCS_CIGD11", 
		DATUM["D_Cayman_Islands_Geodetic_Datum_2011", 
			ELLIPSOID["GRS_1980", 6378137.0, 298.257222101]], 
		PRIMEM["Greenwich", 0.0], 
		CS[ellipsoidal, 2], 
		AXIS["Latitude (lat)", north, 
			ORDER[1]], 
		AXIS["Longitude (lon)", east, 
			ORDER[2]], 
		ANGLEUNIT["Degree", 0.0174532925199433]], 
	VERTCRS["LCVD61_height", 
		VDATUM["Little_Cayman_Vertical_Datum_1961"], 
		CS[vertical, 1], 
		AXIS["Gravity-related height (H)", up, 
			LENGTHUNIT["Foot", 0.3048]]], 
	ID["EPSG", "9504"]]

Data from @esri/proj-codes

{
  "wkid": 9504,
  "latestWkid": 9504,
  "pcsWkid": 0,
  "gcsWkid": 6135,
  "vcsWkid": 6131,
  "macro": "PE_HVC_CIGD11_LCVD61_HEIGHT_FT",
  "name": "CIGD11_and_LCVD61_height_(ft)",
  "wkt": "HVCOORDSYS[\"CIGD11_and_LCVD61_height_(ft)\",GEOGCS[\"GCS_CIGD11\",DATUM[\"D_Cayman_Islands_Geodetic_Datum_2011\",SPHEROID[\"GRS_1980\",6378137.0,298.257222101]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]],VERTCS[\"LCVD61_height\",VDATUM[\"Little_Cayman_Vertical_Datum_1961\"],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",1.0],UNIT[\"Foot\",0.3048]]]",
  "wkt2": "COMPOUNDCRS[\"CIGD11_and_LCVD61_height_(ft)\",GEOGCRS[\"GCS_CIGD11\",DATUM[\"D_Cayman_Islands_Geodetic_Datum_2011\",ELLIPSOID[\"GRS_1980\",6378137.0,298.257222101]],PRIMEM[\"Greenwich\",0.0],CS[ellipsoidal,2],AXIS[\"Latitude (lat)\",north,ORDER[1]],AXIS[\"Longitude (lon)\",east,ORDER[2]],ANGLEUNIT[\"Degree\",0.0174532925199433]],VERTCRS[\"LCVD61_height\",VDATUM[\"Little_Cayman_Vertical_Datum_1961\"],CS[vertical,1],AXIS[\"Gravity-related height (H)\",up,LENGTHUNIT[\"Foot\",0.3048]]],ID[\"EPSG\",\"9504\"]]",
  "description": "CIGD11 + LCVD61 height (ft)",
  "authority": "EPSG",
  "version": "10.013(13.2.0)",
  "deprecated": "no",
  "areaname": "Cayman Islands - Little Cayman",
  "extent": {
    "slat": 19.63,
    "nlat": 19.74,
    "llon": -80.14,
    "rlon": -79.93
  }
}