Read Referer to determine the URI of the resource where the HTTP request message originated. Referer allows the server application to generate back-links to the source of the request. If Referer is a partial URI, it should be interpreted as a relative path to the URL property. 

The Referer property is not set when the URL of the HTTP request was obtained from a source that does not have its own URI, such as input from the user keyboard. 

DerivedFrom 

From 

RemoteAddr 

RemoteHost 

UserAgent 

Properties That Describe the Web Client