use strict;
foreach my $field (param)
{
  #cover multivalued fields like checkboxes? Is this correct?
  foreach my $value (param($field))
  {
     #not sure what the mapping and undef are doing with the field variable?
     next if exists
       { map {$_ => undef } qw(city state country) } -> { $field };
     #process non blank thedata variable
     if($value !~ /^\s*$/)
     {
         my $thedata .= "$field\:\t$value<br />";
         
     }
  }

}