GSB-IRF - EPSG:10260

WKT

GEOGCS["GSB-IRF", 
	DATUM["Generalstabens_System_Bornholm_Intermediate_Datum", 
		SPHEROID["Danish_1876", 6377019.27, 300.0]], 
	PRIMEM["Greenwich", 0.0], 
	UNIT["Degree", 0.0174532925199433]]

WKT2

GEOGCRS["GSB-IRF", 
	DATUM["Generalstabens_System_Bornholm_Intermediate_Datum", 
		ELLIPSOID["Danish_1876", 6377019.27, 300.0]], 
	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", "10260"]]

Data from @esri/proj-codes

{
  "wkid": 10260,
  "latestWkid": 10260,
  "macro": "PE_GCS_GSB_IRF",
  "name": "GSB-IRF",
  "wkt": "GEOGCS[\"GSB-IRF\",DATUM[\"Generalstabens_System_Bornholm_Intermediate_Datum\",SPHEROID[\"Danish_1876\",6377019.27,300.0]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]]",
  "wkt2": "GEOGCRS[\"GSB-IRF\",DATUM[\"Generalstabens_System_Bornholm_Intermediate_Datum\",ELLIPSOID[\"Danish_1876\",6377019.27,300.0]],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\",\"10260\"]]",
  "description": "GSB-IRF",
  "authority": "EPSG",
  "version": "10.088(13.2.0)",
  "deprecated": "no",
  "areaname": "Denmark - onshore Bornholm",
  "extent": {
    "slat": 54.94,
    "nlat": 55.38,
    "llon": 14.59,
    "rlon": 15.25
  }
}