Chapter 1 What’s New for FortiOS 5.0 : WAN optimization and Web Caching : Web proxy URL debugging
  
Web proxy URL debugging
You can use the following CLI commands to get debugging information that shows how the web cache is handling specific URLs. You can debug web caching for a single web page (such as docs.fortinet.com/fgt40mr3.html) or for all requests to a URL pattern (such as docs.fortinet.com to debug all connections to any page on docs.fortinet.com). Wildcard characters and regular expressions are not supported.
Normally you would use this feature if the web cache was not caching specific pages and sites. It makes it easier to get debug information just for the pages causing the problem. This feature works for web caching enabled in any security policy including web proxy and WAN optimization security policies.