Sample function to remove the archive pages from post categories / tags. Useful if you want to disallow access

Remove_wordpress_cat_tag_archives.txt

/**
 * Adjusts taxonomies to remove their index page (archive page)
 *
 * Removing the 'publicly_queryable' property and setting 'rewrite' to false to disallow direct URL linking to the name of the term (no archive page
 * needed). requires permalinks once to get this to work.
 *
 * @param $args - Arguments used to register taxonomy
 * @param $taxonomy_name - Taxonomy Key
 * @param $object_type - Array of names of object types for the taxonomy
 */
  function remove_archives_for_taxonomies($args, $taxonomy_name, $object_type){

      if($taxonomy_name == 'post_tag' || $taxonomy_name == 'category'){
          $args['publicly_queryable'] = false;
          $args['rewrite'] = false;
      }

      return $args;
  }
add_action('register_taxonomy_args', 'remove_archives_for_taxonomies', 10, 3);