diff --git a/lib/OpenLayers/BaseTypes/LonLat.js b/lib/OpenLayers/BaseTypes/LonLat.js
index b62e6624c6..1c5882036f 100644
--- a/lib/OpenLayers/BaseTypes/LonLat.js
+++ b/lib/OpenLayers/BaseTypes/LonLat.js
@@ -11,23 +11,27 @@ OpenLayers.LonLat.prototype = {
 
     /** 
      * APIProperty: lon
-     * {Float}
+     * {Float} The x-axis coodinate in map units
      */
     lon: 0.0,
     
     /** 
      * APIProperty: lat
-     * {Float}
+     * {Float} The y-axis coordinate in map units
      */
     lat: 0.0,
 
     /**
      * Constructor: OpenLayers.LonLat
-     * Create a new OpenLayers.LonLat instance
+     * Create a new map location.
      *
      * Parameters:
-     * lon - {Number} The lon coordinate
-     * lat - {Number} The lat coordinate
+     * lon - {Number} The x-axis coordinate in map units.  If your map is in
+     *     a geographic projection, this will be the Longitude.  Otherwise,
+     *     it will be the x coordinate of the map location in your map units.
+     * lat - {Number} The y-axis coordinate in map units.  If your map is in
+     *     a geographic projection, this will be the Latitude.  Otherwise,
+     *     it will be the y coordinate of the map location in your map units.
      */
     initialize: function(lon, lat) {
         this.lon = parseFloat(lon);