Internet Direct (Indy) Version 9.0.1 Beta
TIdRequestHeaderInfo.Referer
Specifies the address where a request URI was obtained.

property Referer: string;
Description
Referer is a String property that allows the client to specify, to the server, the address of the resource from which the Request URI was obtained. The Referer header allows a server to generate lists of links used to access the resource, and may be used for logging or caching purposes.

If the Referer value is a relative URI, it should be interpreted relative to the URI for the RequestI, and may not include a fragment.