What is custom_url_rewrite_outbound in Drupal?

Syn: custom_url_rewrite_outbound(&$path, &$options, $original_path)

1. custom_url_rewrite_outbound is not a hook, it's a function.
2. You can add to settings.php to alter all links generated by Drupal.
3. This function is called from url().
4. 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.

Parameters:

$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.