$name  = '' unless defined $name;
	$rank  = '' unless defined $rank;
	$c_num = '' unless defined $c_num;


##</code><code>##

	foreach ($name, $rank, $c_num) { defined or $_ = '' }


##</code><code>##

	$_ = '' for grep !defined => ($name, $rank, $c_num);
 

##</code><code>##

	$name  = '' if weight($name)  == weight($duck);
	$rank  = '' if weight($rank)  == weight($duck);
	$c_num = '' if weight($c_num) == weight($duck);