I'm not sure how best to describe this (as you can clearly tell from the title) so I'll give you an example: I have a multisite Drupal installation. Each of the sites' sitemap.xml files are located on the server at /sites/example.com/files though with a browser (and to search engines) it is accessible at example.com/sitemap.xml I was wondering how this was achieved? Is this called Virtual Directory? Thank you