Slovenia 1996 + SVS2000 height - EPSG:10686

WKT

HVCOORDSYS["Slovenia_1996_and_SVS2000_height", 
	GEOGCS["GCS_Slovenia_1996", 
		DATUM["D_Slovenia_Geodetic_Datum_1996", 
			SPHEROID["GRS_1980", 6378137.0, 298.257222101]], 
		PRIMEM["Greenwich", 0.0], 
		UNIT["Degree", 0.0174532925199433]], 
	VERTCS["SVS2000", 
		VDATUM["Slovenian_Vertical_System_2000"], 
		PARAMETER["Vertical_Shift", 0.0], 
		PARAMETER["Direction", 1.0], 
		UNIT["Meter", 1.0]]]

WKT2

COMPOUNDCRS["Slovenia_1996_and_SVS2000_height", 
	GEOGCRS["GCS_Slovenia_1996", 
		DATUM["D_Slovenia_Geodetic_Datum_1996", 
			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["SVS2000", 
		VDATUM["Slovenian_Vertical_System_2000"], 
		CS[vertical, 1], 
		AXIS["Gravity-related height (H)", up, 
			LENGTHUNIT["Meter", 1.0]]], 
	ID["EPSG", "10686"]]

Data from @esri/proj-codes

{
  "wkid": 10686,
  "latestWkid": 10686,
  "pcsWkid": 0,
  "gcsWkid": 4765,
  "vcsWkid": 5779,
  "macro": "PE_HVC_SLOVENIA_1996_SVS2000_HEIGHT",
  "name": "Slovenia_1996_and_SVS2000_height",
  "wkt": "HVCOORDSYS[\"Slovenia_1996_and_SVS2000_height\",GEOGCS[\"GCS_Slovenia_1996\",DATUM[\"D_Slovenia_Geodetic_Datum_1996\",SPHEROID[\"GRS_1980\",6378137.0,298.257222101]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]],VERTCS[\"SVS2000\",VDATUM[\"Slovenian_Vertical_System_2000\"],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",1.0],UNIT[\"Meter\",1.0]]]",
  "wkt2": "COMPOUNDCRS[\"Slovenia_1996_and_SVS2000_height\",GEOGCRS[\"GCS_Slovenia_1996\",DATUM[\"D_Slovenia_Geodetic_Datum_1996\",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[\"SVS2000\",VDATUM[\"Slovenian_Vertical_System_2000\"],CS[vertical,1],AXIS[\"Gravity-related height (H)\",up,LENGTHUNIT[\"Meter\",1.0]]],ID[\"EPSG\",\"10686\"]]",
  "description": "Slovenia 1996 + SVS2000 height",
  "authority": "EPSG",
  "version": "11.022(13.5.0)",
  "deprecated": "no",
  "areaname": "Slovenia - onshore",
  "extent": {
    "slat": 45.42,
    "nlat": 46.88,
    "llon": 13.38,
    "rlon": 16.61
  }
}