=item sleep
-This is identical to Perl's builtin C<sleep()> function
-for suspending the execution of the current for process
-for certain number of seconds, see L<perlfunc/sleep>.
+This is functionally identical to Perl's builtin C<sleep()> function
+for suspending the execution of the current for process for certain
+number of seconds, see L<perlfunc/sleep>. There is one signifanct
+difference, however: C<POSIX::sleep()> returns the number of
+B<unslept> seconds, while the C<CORE::sleep()> returns the
+number of slept seconds.
=item sprintf