Sometimes, in Zend Framework, you need to add custom routes in your web application. One of the options is to define the routes in a XML file and load it from the bootstrap.
The advantage of this approach for routing is that you add your routes in the XML file, without the need to touch the PHP code, which makes it very easy for the web app itself to generate or update the routes. This is very useful when when you building a CMS or some SEO related functionality, because you can allow the customer to set their own worded urls according to their SEO optimization strategies.