- custom_url_rewrite_outbound is not a hook, it's a function.
- You can add to settings.php to alter all links generated by Drupal.
- This function is called from url().
- This function is called very frequently (100+ times per page) so performance is critical.
This function should change the value of $path and $options by reference.
$path: The alias of the $original_path as defined in the database. If there is no match in the database it'll be the same as $original_path
$options: An array of link attributes such as querystring and fragment. See url().
$original_path: The unaliased Drupal path that is being linked to.