# if there is no value provided but a default value in parameters, get it
if ( $value eq '' ) {
- $value = $tagslib->{$tag}->{$subfield}->{defaultvalue};
+ $value = $tagslib->{$tag}->{$subfield}->{defaultvalue} // q{};
# get today date & replace <<YYYY>>, <<MM>>, <<DD>> if provided in the default value
my $today_dt = dt_from_string;
my $parentbiblio = $input->param('parentbiblionumber');
my $breedingid = $input->param('breedingid');
my $z3950 = $input->param('z3950');
-my $op = $input->param('op');
+my $op = $input->param('op') // q{};
my $mode = $input->param('mode');
my $frameworkcode = $input->param('frameworkcode');
my $redirect = $input->param('redirect');
my $userflags = 'edit_catalogue';
-my $changed_framework = $input->param('changed_framework');
+my $changed_framework = $input->param('changed_framework') // q{};
$frameworkcode = &GetFrameworkCode($biblionumber)
if ( $biblionumber and not( defined $frameworkcode) and $op ne 'addbiblio' );