Twenty-five years ago, Carnegie Mellon University professor Scott E. Fahlman says, he was the first to use three keystrokes — a colon followed by a hyphen and a parenthesis — as a horizontal “smiley face” in a computer message. The Associated Press reports.

… Fahlman posted the emoticon in a message to an online electronic bulletin board at 11:44 a.m. on Sept. 19, 1982, during a discussion about the limits of online humor and how to denote comments meant to be taken lightly.

“I propose the following character sequence for joke markers: :-),” wrote Fahlman. “Read it sideways.”

The suggestion gave computer users a way to convey humor or positive feelings with a smile — or the opposite sentiments by reversing the parenthesis to form a frown.

Carnegie Mellon said Fahlman’s smileys spread from its campus to other universities, then businesses.