diff --git a/MapControl/Shared/Etrs89UtmProjection.cs b/MapControl/Shared/Etrs89UtmProjection.cs
index 09ed8ddf..2d258f55 100644
--- a/MapControl/Shared/Etrs89UtmProjection.cs
+++ b/MapControl/Shared/Etrs89UtmProjection.cs
@@ -3,7 +3,7 @@
 namespace MapControl
 {
     /// <summary>
-    /// ETRS89 Universal Transverse Mercator Projection.
+    /// ETRS89 Universal Transverse Mercator Projection - EPSG:25828 to EPSG:25838.
     /// </summary>
     public class Etrs89UtmProjection : TransverseMercatorProjection
     {
diff --git a/MapControl/Shared/Nad27UtmProjection.cs b/MapControl/Shared/Nad27UtmProjection.cs
index 8d508993..e145b135 100644
--- a/MapControl/Shared/Nad27UtmProjection.cs
+++ b/MapControl/Shared/Nad27UtmProjection.cs
@@ -3,7 +3,7 @@
 namespace MapControl
 {
     /// <summary>
-    /// NAD27 Universal Transverse Mercator Projection.
+    /// NAD27 Universal Transverse Mercator Projection - EPSG:26701 to EPSG:26722.
     /// </summary>
     public class Nad27UtmProjection : TransverseMercatorProjection
     {
diff --git a/MapControl/Shared/Nad83UtmProjection.cs b/MapControl/Shared/Nad83UtmProjection.cs
index 5e78965e..5b03bed2 100644
--- a/MapControl/Shared/Nad83UtmProjection.cs
+++ b/MapControl/Shared/Nad83UtmProjection.cs
@@ -3,7 +3,7 @@
 namespace MapControl
 {
     /// <summary>
-    /// NAD83 Universal Transverse Mercator Projection.
+    /// NAD83 Universal Transverse Mercator Projection - EPSG:26901 to EPSG:26923.
     /// </summary>
     public class Nad83UtmProjection : TransverseMercatorProjection
     {
diff --git a/MapControl/Shared/TransverseMercatorProjection.cs b/MapControl/Shared/TransverseMercatorProjection.cs
index f53b6f69..55b8aca9 100644
--- a/MapControl/Shared/TransverseMercatorProjection.cs
+++ b/MapControl/Shared/TransverseMercatorProjection.cs
@@ -56,7 +56,7 @@ namespace MapControl
             }
         }
 
-        private double MeridianDistance(double phi) // (3-21)
+        private double MeridianDistance(double phi)
         {
             var e2 = (2d - Flattening) * Flattening;
             var e4 = e2 * e2;
@@ -66,7 +66,7 @@ namespace MapControl
                 ((1d - e2 / 4d - 3d * e4 / 64d - 5d * e6 / 256d) * phi -
                 (3d * e2 / 8d + 3d * e4 / 32d + 45d * e6 / 1024d) * Math.Sin(2d * phi) +
                 (15d * e4 / 256d + 45d * e6 / 1024d) * Math.Sin(4d * phi) -
-                35d * e6 / 3072d * Math.Sin(6d * phi));
+                35d * e6 / 3072d * Math.Sin(6d * phi)); // (3-21)
         }
 
         public override Matrix RelativeScale(double latitude, double longitude)
diff --git a/MapControl/Shared/Wgs84UtmProjection.cs b/MapControl/Shared/Wgs84UtmProjection.cs
index 7263ff42..9e9bb624 100644
--- a/MapControl/Shared/Wgs84UtmProjection.cs
+++ b/MapControl/Shared/Wgs84UtmProjection.cs
@@ -9,7 +9,8 @@ namespace MapControl
     }
 
     /// <summary>
-    /// WGS84 Universal Transverse Mercator Projection.
+    /// WGS84 Universal Transverse Mercator Projection -
+    /// EPSG:32601 to EPSG:32660 and EPSG:32701 to EPSG:32760.
     /// </summary>
     public class Wgs84UtmProjection : TransverseMercatorProjection
     {