Black Sea depth - EPSG:5336

WKT

VERTCS["Black_Sea_Depth", 
	VDATUM["Black_Sea"], 
	PARAMETER["Vertical_Shift", 0.0], 
	PARAMETER["Direction", -1.0], 
	UNIT["Meter", 1.0]]

WKT2

VERTCRS["Black_Sea_Depth", 
	VDATUM["Black_Sea"], 
	CS[vertical, 1], 
	AXIS["Gravity-related height (H)", down, 
		LENGTHUNIT["Meter", 1.0]], 
	ID["EPSG", "5336"]]

Data from @esri/proj-codes

{
  "wkid": 5336,
  "latestWkid": 5336,
  "macro": "PE_VCS_BLACK_SEA_D",
  "name": "Black_Sea_Depth",
  "wkt": "VERTCS[\"Black_Sea_Depth\",VDATUM[\"Black_Sea\"],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",-1.0],UNIT[\"Meter\",1.0]]",
  "wkt2": "VERTCRS[\"Black_Sea_Depth\",VDATUM[\"Black_Sea\"],CS[vertical,1],AXIS[\"Gravity-related height (H)\",down,LENGTHUNIT[\"Meter\",1.0]],ID[\"EPSG\",\"5336\"]]",
  "description": "Black Sea depth",
  "authority": "EPSG",
  "version": "7.6.4(10.2.0)",
  "deprecated": "no",
  "areaname": "Georgia - onshore",
  "extent": {
    "slat": 41.04,
    "nlat": 43.59,
    "llon": 39.99,
    "rlon": 46.72
  }
}