popsu-d7/sites/all/modules/xmlsitemap/xmlsitemap_custom/xmlsitemap_custom.install

<?php

/**
 * @file
 * Install and uninstall schema and functions for the xmlsitemap_custom module.
 */

/**
 * Implements hook_uninstall().
 */
function xmlsitemap_custom_uninstall() {
  drupal_load('module', 'xmlsitemap');
  xmlsitemap_link_delete_multiple(array('type' => 'custom'));
}