S-JTSK [JTSK03] - ESRI:115848

WKT

VERTCS["S-
	JTSK_[JTSK03]", 
	DATUM["S-
		JTSK_[JTSK03]", 
		SPHEROID["Bessel_1841", 6377397.155, 299.1528128]], 
	PARAMETER["Vertical_Shift", 0.0], 
	PARAMETER["Direction", 1.0], 
	UNIT["Meter", 1.0]]

WKT2

VERTCRS["S-
	JTSK_[JTSK03]", 
	DATUM["S-
		JTSK_[JTSK03]", 
		ELLIPSOID["Bessel_1841", 6377397.155, 299.1528128]], 
	CS[vertical, 1], 
	AXIS["Ellipsoidal height (h)", up, 
		LENGTHUNIT["Meter", 1.0]], 
	ID["Esri", "115848"]]

Data from @esri/proj-codes

{
  "wkid": 115848,
  "latestWkid": 115848,
  "macro": "PE_VCS_S_JTSK_JTSK03",
  "name": "S-JTSK_[JTSK03]",
  "wkt": "VERTCS[\"S-JTSK_[JTSK03]\",DATUM[\"S-JTSK_[JTSK03]\",SPHEROID[\"Bessel_1841\",6377397.155,299.1528128]],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",1.0],UNIT[\"Meter\",1.0]]",
  "wkt2": "VERTCRS[\"S-JTSK_[JTSK03]\",DATUM[\"S-JTSK_[JTSK03]\",ELLIPSOID[\"Bessel_1841\",6377397.155,299.1528128]],CS[vertical,1],AXIS[\"Ellipsoidal height (h)\",up,LENGTHUNIT[\"Meter\",1.0]],ID[\"Esri\",\"115848\"]]",
  "description": "S-JTSK [JTSK03]",
  "authority": "Esri",
  "version": "10.7.1",
  "deprecated": "no",
  "areaname": "Slovakia",
  "extent": {
    "slat": 47.73,
    "nlat": 49.61,
    "llon": 16.84,
    "rlon": 22.56
  }
}