BBT2000 - EPSG:10475

WKT

GEOGCS["BBT2000", 
	DATUM["Brenner_Base_Tunnel_2000", 
		SPHEROID["WGS_1984", 6378137.0, 298.257223563]], 
	PRIMEM["Greenwich", 0.0], 
	UNIT["Degree", 0.0174532925199433]]

WKT2

GEOGCRS["BBT2000", 
	DATUM["Brenner_Base_Tunnel_2000", 
		ELLIPSOID["WGS_1984", 6378137.0, 298.257223563]], 
	PRIMEM["Greenwich", 0.0], 
	CS[ellipsoidal, 2], 
	AXIS["Latitude (lat)", north, 
		ORDER[1]], 
	AXIS["Longitude (lon)", east, 
		ORDER[2]], 
	ANGLEUNIT["Degree", 0.0174532925199433], 
	ID["EPSG", "10475"]]

Data from @esri/proj-codes

{
  "wkid": 10475,
  "latestWkid": 10475,
  "macro": "PE_GCS_BBT2000",
  "name": "BBT2000",
  "wkt": "GEOGCS[\"BBT2000\",DATUM[\"Brenner_Base_Tunnel_2000\",SPHEROID[\"WGS_1984\",6378137.0,298.257223563]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]]",
  "wkt2": "GEOGCRS[\"BBT2000\",DATUM[\"Brenner_Base_Tunnel_2000\",ELLIPSOID[\"WGS_1984\",6378137.0,298.257223563]],PRIMEM[\"Greenwich\",0.0],CS[ellipsoidal,2],AXIS[\"Latitude (lat)\",north,ORDER[1]],AXIS[\"Longitude (lon)\",east,ORDER[2]],ANGLEUNIT[\"Degree\",0.0174532925199433],ID[\"EPSG\",\"10475\"]]",
  "description": "BBT2000",
  "authority": "EPSG",
  "version": "10.095(13.3.0)",
  "deprecated": "no",
  "areaname": "Europe - Brenner",
  "extent": {
    "slat": 46.45,
    "nlat": 47.33,
    "llon": 11.04,
    "rlon": 11.91
  }
}