What does r= do?

Hi,

In the following google search url, which i found on a random site, what does the r query string key mean?

http://www.google.com/search?q=dave&r=website.com

Is there any benefit in telling google where the search request came from?

 

r is the query for referal.

 

But why tell google that the search is being referred from your site? Won't that be in the header of the request anyway?

 

Some browsers, or users disable referers, doing this way double checks it. Like how you do a bank reconciliation in accounting principals. http://en.wikipedia.org/wiki/Bank_reconciliation