AnaaS mentioned that My E-mail program has an option called "blind c/c,"

BCC in itself is an example of how usage shifts. I was always taught that it stood for Blind Carbon Copy, but now that e-mail has become so well established, BCC is now explained as Blind Courtesy, or Blind Complimentary, Copy. Saves having to explain to one's 5 year old what carbon paper was, I guess.