[S24] made all parameters optional

Also added back some clarification that optional parameters can
be implemented in other ways, for example using multi dispatch.

S24-testing.pod

@@ -14,7 +14,7 @@ Synopsis 24: Testing
     Created: 30 Dec 2010
 
     Last Modified: 31 Dec 2010
-    Version: 5
+    Version: 6
 
 =head1 SYNOPSIS
 
@@ -61,19 +61,20 @@ file, or if the call occurred between calling two test functions
 
 =head2 Test functions
 
-All test functions take a description argument, which will be
-printed along with the C<ok> or C<not ok> result and the test
-number. Except in the case of the functions C<pass> and C<flunk>,
-this description is optional.
+All test functions take an optional description argument, which
+will be printed along with the C<ok> or C<not ok> result and the test
+number. Note that what is displayed as optional parameters in the list
+below might as well be implemented by some other mechanism, such as
+several C<multi sub>s. Such details are left as implementation-dependent.
 
 The names of positional parameters are non-normative, so supplying the
 positional arguments to these test files by name is discouraged.
 
 All of the following functions are exported by default:
 
     # unconditional passing/failing
-    pass($desc)
-    flunk($desc)
+    pass($desc?)
+    flunk($desc?)
 
     # evaluates $cond in boolean context
     ok(Mu $cond, $desc?)