Document doc = Application.DocumentManager.MdiActiveDocument; Editor ed = doc.Editor; ed.WriteMessage(RXObject.GetClass(typeof(Polyline)).DxfName + "\n"); ed.WriteMessage(RXObject.GetClass(typeof(Polyline2d)).DxfName + "\n"); ed.WriteMessage(RXObject.GetClass(typeof(Polyline3d)).DxfName + "\n");