A number sequence typed into calculators or other digital devices by immature junior high students to display a naughty yet juvenile message. The message, when flipped upside down, clearly reads, "BOOBLESS."
See also
7734206
Bobby: "Hey, look at this!"
Johnny: "What?"
Bobby: "This describes our stupid teacher... ::types into calculator, holds it up to Johnny::
...she's BOOBLESS!!!"