You could edit form-listing.php.
Add in:
'exclude' => '36, 37, 38, 39',
to wp_dropdown_categories. Replace the numbers above with the ID numbers of whatever categories you want excluded.
...
You could edit form-listing.php.
Add in:
'exclude' => '36, 37, 38, 39',
to wp_dropdown_categories. Replace the numbers above with the ID numbers of whatever categories you want excluded.
...
