> And due to a terrible oversight the header is actually mis-spelled and it came out as 'Referer
Well, Cant blame DDG for it though
http://en.wikipedia.org/wiki/HTTP_referrer#Origin_of_the_ter...
No, definitely not, I just wanted to point that out.
I knew about this for years, having stared at a bug for a whole day before I realized it was the header that was misspelled. It never even crossed my mind until I was away from the keyboard for a few hours.
Fixing this will make duckduckgo.com even better, which is awesome.