S-JTSK (Ferro) - EPSG:4818

WKT

GEOGCS["GCS_S_JTSK_Ferro", 
	DATUM["D_S_JTSK", 
		SPHEROID["Bessel_1841", 6377397.155, 299.1528128]], 
	PRIMEM["Ferro", -17.66666666666667], 
	UNIT["Degree", 0.0174532925199433]]

WKT2

GEOGCRS["GCS_S_JTSK_Ferro", 
	DATUM["D_S_JTSK", 
		ELLIPSOID["Bessel_1841", 6377397.155, 299.1528128]], 
	PRIMEM["Ferro", -17.66666666666667, 
		ANGLEUNIT["Degree", 0.0174532925199433]], 
	CS[ellipsoidal, 2], 
	AXIS["Latitude (lat)", north, 
		ORDER[1]], 
	AXIS["Longitude (lon)", east, 
		ORDER[2]], 
	ANGLEUNIT["Degree", 0.0174532925199433], 
	ID["EPSG", "4818"]]

Data from @esri/proj-codes

{
  "wkid": 4818,
  "latestWkid": 4818,
  "macro": "PE_GCS_S_JTSK_FERRO",
  "name": "GCS_S_JTSK_Ferro",
  "wkt": "GEOGCS[\"GCS_S_JTSK_Ferro\",DATUM[\"D_S_JTSK\",SPHEROID[\"Bessel_1841\",6377397.155,299.1528128]],PRIMEM[\"Ferro\",-17.66666666666667],UNIT[\"Degree\",0.0174532925199433]]",
  "wkt2": "GEOGCRS[\"GCS_S_JTSK_Ferro\",DATUM[\"D_S_JTSK\",ELLIPSOID[\"Bessel_1841\",6377397.155,299.1528128]],PRIMEM[\"Ferro\",-17.66666666666667,ANGLEUNIT[\"Degree\",0.0174532925199433]],CS[ellipsoidal,2],AXIS[\"Latitude (lat)\",north,ORDER[1]],AXIS[\"Longitude (lon)\",east,ORDER[2]],ANGLEUNIT[\"Degree\",0.0174532925199433],ID[\"EPSG\",\"4818\"]]",
  "description": "S-JTSK (Ferro)",
  "authority": "EPSG",
  "version": "6.5(8.1.0)",
  "deprecated": "no",
  "areaname": "Europe - Czechoslovakia",
  "extent": {
    "slat": 47.73,
    "nlat": 51.06,
    "llon": 12.09,
    "rlon": 22.56
  }
}