POM08 height - EPSG:7841

WKT

VERTCS["POM08_height", 
	VDATUM["Port_Moresby_2008"], 
	PARAMETER["Vertical_Shift", 0.0], 
	PARAMETER["Direction", 1.0], 
	UNIT["Meter", 1.0]]

WKT2

VERTCRS["POM08_height", 
	VDATUM["Port_Moresby_2008"], 
	CS[vertical, 1], 
	AXIS["Gravity-related height (H)", up, 
		LENGTHUNIT["Meter", 1.0]], 
	ID["EPSG", "7841"]]

Data from @esri/proj-codes

{
  "wkid": 7841,
  "latestWkid": 7841,
  "macro": "PE_VCS_POM08_HT",
  "name": "POM08_height",
  "wkt": "VERTCS[\"POM08_height\",VDATUM[\"Port_Moresby_2008\"],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",1.0],UNIT[\"Meter\",1.0]]",
  "wkt2": "VERTCRS[\"POM08_height\",VDATUM[\"Port_Moresby_2008\"],CS[vertical,1],AXIS[\"Gravity-related height (H)\",up,LENGTHUNIT[\"Meter\",1.0]],ID[\"EPSG\",\"7841\"]]",
  "description": "POM08 height",
  "authority": "EPSG",
  "version": "9.0(10.6.0)",
  "deprecated": "no",
  "areaname": "Papua New Guinea - onshore - Central province and Gulf province east of 144~E",
  "extent": {
    "slat": -10.42,
    "nlat": -6.67,
    "llon": 144.4,
    "rlon": 149.67
  }
}