wp_delete_category() 是一个小包装wp_delete_term() ( source ).

它有很多钩子，在delete之前的钩子是：

do_action( \'delete_term_taxonomy\', $tt_id );

do_action( \'deleted_term_taxonomy\', $tt_id );
do_action(\'delete_term\', $term, $tt_id, $taxonomy);
do_action("delete_$taxonomy", $term, $tt_id);