add_tag_form_fields
Action Hook: Fires after the Add Tag form fields for non-hierarchical taxonomies.
Source: wp-admin/edit-tags.php:525
{$taxonomy}_add_form_fields
Action Hook: Fires after the Add Term form fields.
Source: wp-admin/edit-tags.php:542
redirect_term_location
Filter Hook: Filters the taxonomy redirect destination URL.
Source: wp-admin/edit-tags.php:228
add_category_form_pre
Action Hook (deprecated): Fires before the Add Category form.
Source: wp-admin/edit-tags.php:387