diff --git a/raster/r.watershed/front/r.watershed.html b/raster/r.watershed/front/r.watershed.html
index 5713f611ea3..6772fabf384 100644
--- a/raster/r.watershed/front/r.watershed.html
+++ b/raster/r.watershed/front/r.watershed.html
@@ -316,17 +316,15 @@ <h3>Basin threshold</h3>
 stream segment is determined by the distance between the tributaries
 flowing into it.
 
-<h3>MASK and no data</h3>
+<h3>Masking and no data</h3>
 
 
 The <em>r.watershed</em> program does not require the user to have the
 current geographic region filled with elevation values.  Areas without
-elevation data (masked or NULL cells) are ignored. It is NOT necessary
-to create a raster map (or raster reclassification)
-named <code>MASK</code> for NULL cells.  Areas without elevation data will
-be treated as if they are off the edge of the region. Such areas will
-reduce the memory necessary to run the program.  Masking out
-unimportant areas can significantly reduce processing time if the
+elevation data (masked or NULL cells, i.e., no data) are ignored and
+treated as if they were outside the region. Masking out
+unimportant areas can significantly reduce processing time and memory
+requirements if the
 watersheds of interest occupy a small percentage of the overall area.
 
 <p>
@@ -357,7 +355,7 @@ <h3>Further processing of output layers</h3>
 module, a number of approaches may be considered.
 
 <ol>
-<li>Use a resample of the basins catchment raster map as a MASK.<br>
+<li>Use a resample of the basins catchment raster map as a raster mask.<br>
   The equivalent vector map method is similar
   using <em><a href="v.select.html">v.select</a></em> or
   <em><a href="v.overlay.html">v.overlay</a></em>.</li>
@@ -386,7 +384,7 @@ <h3>Further processing of output layers</h3>
 with
 <em><a href="r.thin.html">r.thin</a></em>. Each stream segment in the
 vector map will have the value of the associated basin. To isolate
-subbasins and streams for a larger basin, a MASK for the larger basin
+subbasins and streams for a larger basin, a mask for the larger basin
 can be created with
 <em><a href="r.water.outlet.html">r.water.outlet</a></em>. The stream
 segments output serves as a guide where to place the outlet point used