--- a/src/ai/api/ai_road.hpp	Sun Jun 15 22:18:10 2008 +0000
+++ b/src/ai/api/ai_road.hpp	Sun Jun 15 22:37:35 2008 +0000
@@ -204,7 +204,7 @@
 	 * @param front The tile exactly in front of the depot.
 	 * @pre AIMap::IsValidTile(tile).
 	 * @pre AIMap::IsValidTile(front).
-	 * @pre Tile is not equal to front.
+	 * @pre 'tile' is not equal to 'front', but in a straight line of it.
 	 * @exception AIError::ERR_FLAT_LAND_REQUIRED
 	 * @exception AIError::ERR_AREA_NOT_CLEAR
 	 * @return Whether the road depot has been/can be build or not.
@@ -220,7 +220,7 @@
 	 * @param drive_through Whether to make the station drive through or not.
 	 * @pre AIMap::IsValidTile(tile).
 	 * @pre AIMap::IsValidTile(front).
-	 * @pre 'tile' is not equal to 'front'.
+	 * @pre 'tile' is not equal to 'front', but in a straight line of it.
 	 * @exception AIError::ERR_OWNED_BY_ANOTHER_COMPANY
 	 * @exception AIError::ERR_AREA_NOT_CLEAR
 	 * @exception AIError::ERR_FLAT_LAND_REQUIRED