added comment

applications/utilities/mesh/generation/snappyHexMesh/snappyHexMeshDict

@@ -209,6 +209,8 @@ snapControls
 // Settings for the layer addition.
 addLayersControls
 {
+    // Are the thickness parameters below relative to the undistorted
+    // size of the refined cell outside layer (true) or absolute sizes (false).
     relativeSizes true;
 
     // Per final patch (so not geometry!) the layer information
@@ -230,14 +232,13 @@ addLayersControls
 
 
     //- Wanted thickness of final added cell layer. If multiple layers
-    //  is the
-    //  thickness of the layer furthest away from the wall.
-    //  Relative to undistorted size of cell outside layer.
+    //  is the thickness of the layer furthest away from the wall.
+    //  See relativeSizes parameter.
     finalLayerThickness 0.3;
 
     //- Minimum thickness of cell layer. If for any reason layer
     //  cannot be above minThickness do not add layer.
-    //  Relative to undistorted size of cell outside layer.
+    //  See relativeSizes parameter.
     minThickness 0.25;
 
     //- If points get not extruded do nGrow layers of connected faces that are