Baltic 1986 height - EPSG:9650

WKT

VERTCS["Baltic_1986_height", 
	VDATUM["Baltic_1986"], 
	PARAMETER["Vertical_Shift", 0.0], 
	PARAMETER["Direction", 1.0], 
	UNIT["Meter", 1.0]]

WKT2

VERTCRS["Baltic_1986_height", 
	VDATUM["Baltic_1986"], 
	CS[vertical, 1], 
	AXIS["Gravity-related height (H)", up, 
		LENGTHUNIT["Meter", 1.0]], 
	ID["EPSG", "9650"]]

Data from @esri/proj-codes

{
  "wkid": 9650,
  "latestWkid": 9650,
  "macro": "PE_VCS_BALTIC_1986_HT",
  "name": "Baltic_1986_height",
  "wkt": "VERTCS[\"Baltic_1986_height\",VDATUM[\"Baltic_1986\"],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",1.0],UNIT[\"Meter\",1.0]]",
  "wkt2": "VERTCRS[\"Baltic_1986_height\",VDATUM[\"Baltic_1986\"],CS[vertical,1],AXIS[\"Gravity-related height (H)\",up,LENGTHUNIT[\"Meter\",1.0]],ID[\"EPSG\",\"9650\"]]",
  "description": "Baltic 1986 height",
  "authority": "EPSG",
  "version": "10.016(12.9.0)",
  "deprecated": "no",
  "areaname": "Poland - onshore",
  "extent": {
    "slat": 49,
    "nlat": 54.89,
    "llon": 14.14,
    "rlon": 24.15
  }
}