@var{feature}.
If provided, @var{subfeatures} should be a list of symbols indicating
-a set of specific subfeatures provided by this version of @var{feature}.
-You can test the presence of a subfeature using @code{featurep}.
+a set of specific subfeatures provided by this version of
+@var{feature}. You can test the presence of a subfeature using
+@code{featurep}. The idea of subfeatures is that you use them when a
+package (which is one @var{feature}) is complex enough to make it
+useful to give names to various parts or functionalities of the
+package, which might or might not be loaded, or might or might not be
+present in a given version. @xref{Network Feature Testing}, for
+an example.
@smallexample
features