Here’s One of my favorite bits of geek lore.

Did you know that EVERY TIME you click a link on the internet, you send a misspelled word out into the ether? Yep, when you click a link in your browser, the browser sends the web page you are browsing to the location of the page you were just at. This field, sent by your browser, is called HTTP_REFERER. That’s right REFERER, not REFERRER. It’s a misspelling. This misspelling of the word has been part of the official HTTP protocol standard since 1996. By the time anyone noticed it, it was too late, and legions of programmers have had to type a misspelled word ever since to get the value of this field. And now you know…the rest of the story.