=item setgid
-Sets the real group identifier for this process.
-Identical to assigning a value to the Perl's builtin C<$)> variable,
-see L<perlvar/$UID>.
+Sets the real group identifier and the effective group identifier for
+this process. Similar to assigning a value to the Perl's builtin
+C<$)> variable, see L<perlvar/$GID>, except that the latter
+will change only the real user identifier, and that the setgid()
+uses only a single numeric argument, as opposed to a space-separated
+list of numbers.
=item setjmp
=item setuid
-Sets the real user identifier for this process.
-Identical to assigning a value to the Perl's builtin C<$E<lt>> variable,
-see L<perlvar/$UID>.
+Sets the real user identifier and the effective user identifier for
+this process. Similar to assigning a value to the Perl's builtin
+C<$E<lt>> variable, see L<perlvar/$UID>, except that the latter
+will change only the real user identifier.
=item sigaction
$str = POSIX::strftime( "%A, %B %d, %Y", 0, 0, 0, 12, 11, 95, 2 );
print "$str\n";
+See also L<Time::Piece>.
+
=item strlen
strlen() is C-specific, use C<length()> instead, see L<perlfunc/length>.
$tmpfile = POSIX::tmpnam();
-See also L<File::Temp>.
+For security reasons, which are probably detailed in your system's
+documentation for the C library tmpnam() function, this interface
+should not be used; instead see L<File::Temp>.
=item tolower