Read in "Shampoo Planet" (Douglas Coupland):

"We discuss the future a lot, my friends and me. My best friend, Harmony, (...) thinks the future will be like rap music and computer codes, filled with Xs, Qs, and Zs: "Letters liberated by the computer keyboard."

Why do I blog this? I often find funny how sci-fi pieces (novels, manga, comics, anime, movies) use x,y,z as well as crazy numbers or even greek signs to talk about devices of the future. Which is why I like that quote.