WGS 1972 BE - ESRI:115909

WKT

VERTCS["WGS_1972_BE", 
	DATUM["D_WGS_1972_BE", 
		SPHEROID["WGS_1972", 6378135.0, 298.26]], 
	PARAMETER["Vertical_Shift", 0.0], 
	PARAMETER["Direction", 1.0], 
	UNIT["Meter", 1.0]]

WKT2

VERTCRS["WGS_1972_BE", 
	DYNAMIC[
		FRAMEEPOCH[1972.0]], 
	DATUM["D_WGS_1972_BE", 
		ELLIPSOID["WGS_1972", 6378135.0, 298.26]], 
	CS[vertical, 1], 
	AXIS["Ellipsoidal height (h)", up, 
		LENGTHUNIT["Meter", 1.0]], 
	ID["Esri", "115909"]]

Data from @esri/proj-codes

{
  "wkid": 115909,
  "latestWkid": 115909,
  "macro": "PE_VCS_WGS_1972_BE",
  "name": "WGS_1972_BE",
  "wkt": "VERTCS[\"WGS_1972_BE\",DATUM[\"D_WGS_1972_BE\",SPHEROID[\"WGS_1972\",6378135.0,298.26]],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",1.0],UNIT[\"Meter\",1.0]]",
  "wkt2": "VERTCRS[\"WGS_1972_BE\",DYNAMIC[FRAMEEPOCH[1972.0]],DATUM[\"D_WGS_1972_BE\",ELLIPSOID[\"WGS_1972\",6378135.0,298.26]],CS[vertical,1],AXIS[\"Ellipsoidal height (h)\",up,LENGTHUNIT[\"Meter\",1.0]],ID[\"Esri\",\"115909\"]]",
  "description": "WGS 1972 BE",
  "authority": "Esri",
  "version": "13.2.0",
  "deprecated": "no",
  "areaname": "World",
  "extent": {
    "slat": -90,
    "nlat": 90,
    "llon": -180,
    "rlon": 180
  }
}