Catania 1965 height - EPSG:9721

WKT

VERTCS["Catania_1965_height", 
	VDATUM["Catania_1965"], 
	PARAMETER["Vertical_Shift", 0.0], 
	PARAMETER["Direction", 1.0], 
	UNIT["Meter", 1.0]]

WKT2

VERTCRS["Catania_1965_height", 
	VDATUM["Catania_1965"], 
	CS[vertical, 1], 
	AXIS["Gravity-related height (H)", up, 
		LENGTHUNIT["Meter", 1.0]], 
	ID["EPSG", "9721"]]

Data from @esri/proj-codes

{
  "wkid": 9721,
  "latestWkid": 9721,
  "macro": "PE_VCS_CATANIA_1965_HEIGHT",
  "name": "Catania_1965_height",
  "wkt": "VERTCS[\"Catania_1965_height\",VDATUM[\"Catania_1965\"],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",1.0],UNIT[\"Meter\",1.0]]",
  "wkt2": "VERTCRS[\"Catania_1965_height\",VDATUM[\"Catania_1965\"],CS[vertical,1],AXIS[\"Gravity-related height (H)\",up,LENGTHUNIT[\"Meter\",1.0]],ID[\"EPSG\",\"9721\"]]",
  "description": "Catania 1965 height",
  "authority": "EPSG",
  "version": "10.021(12.9.0)",
  "deprecated": "no",
  "areaname": "Italy - Sicily onshore",
  "extent": {
    "slat": 36.59,
    "nlat": 38.35,
    "llon": 12.36,
    "rlon": 15.71
  }
}