diff --git a/src/station_type.h b/src/station_type.h
--- a/src/station_type.h
+++ b/src/station_type.h
@@ -34,23 +34,26 @@ enum RoadStopType {
 	ROADSTOP_TRUCK   ///< A standard stop for trucks
 };
 
+/** The facilities a station might be having */
 enum StationFacility {
-	FACIL_TRAIN      = 0x01,
-	FACIL_TRUCK_STOP = 0x02,
-	FACIL_BUS_STOP   = 0x04,
-	FACIL_AIRPORT    = 0x08,
-	FACIL_DOCK       = 0x10,
+	FACIL_NONE       = 0,      ///< The station has no facilities at all
+	FACIL_TRAIN      = 1 << 0, ///< Station with train station
+	FACIL_TRUCK_STOP = 1 << 1, ///< Station with truck stops
+	FACIL_BUS_STOP   = 1 << 2, ///< Station with bus stops
+	FACIL_AIRPORT    = 1 << 3, ///< Station with an airport
+	FACIL_DOCK       = 1 << 4, ///< Station with a dock
 };
 DECLARE_ENUM_AS_BIT_SET(StationFacility);
 typedef SimpleTinyEnumT<StationFacility, byte> StationFacilityByte;
 
+/** The vehicles that may have visited a station */
 enum StationHadVehicleOfType {
-//	HVOT_PENDING_DELETE = 1 << 0, // not needed anymore
-	HVOT_TRAIN    = 1 << 1,
-	HVOT_BUS      = 1 << 2,
-	HVOT_TRUCK    = 1 << 3,
-	HVOT_AIRCRAFT = 1 << 4,
-	HVOT_SHIP     = 1 << 5,
+	HVOT_NONE     = 0,      ///< Station has seen no vehicles
+	HVOT_TRAIN    = 1 << 1, ///< Station has seen a train
+	HVOT_BUS      = 1 << 2, ///< Station has seen a bus
+	HVOT_TRUCK    = 1 << 3, ///< Station has seen a truck
+	HVOT_AIRCRAFT = 1 << 4, ///< Station has seen an aircraft
+	HVOT_SHIP     = 1 << 5, ///< Station has seen a ship
 	/* This bit is used to mark stations. No, it does not belong here, but what
 	 * can we do? ;-) */
 	HVOT_BUOY     = 1 << 6
@@ -58,16 +61,17 @@ enum StationHadVehicleOfType {
 DECLARE_ENUM_AS_BIT_SET(StationHadVehicleOfType);
 typedef SimpleTinyEnumT<StationHadVehicleOfType, byte> StationHadVehicleOfTypeByte;
 
+/** The different catchment areas used */
 enum CatchmentArea {
-	CA_NONE            =  0,
-	CA_BUS             =  3,
-	CA_TRUCK           =  3,
-	CA_TRAIN           =  4,
-	CA_DOCK            =  5,
+	CA_NONE            =  0, ///< Catchment when the station has no facilities
+	CA_BUS             =  3, ///< Catchment for bus stops with "modified catchment" enabled
+	CA_TRUCK           =  3, ///< Catchment for truck stops with "modified catchment" enabled
+	CA_TRAIN           =  4, ///< Catchment for train stations with "modified catchment" enabled
+	CA_DOCK            =  5, ///< Catchment for docks with "modified catchment" enabled
 
-	CA_UNMODIFIED      =  4, ///< Used when _settings_game.station.modified_catchment is false
+	CA_UNMODIFIED      =  4, ///< Catchment for all stations with "modified catchment" disabled
 
-	MAX_CATCHMENT      = 10, ///< Airports have a catchment up to this number.
+	MAX_CATCHMENT      = 10, ///< Maximum catchment for airports with "modified catchment" enabled
 };
 
 enum {