The "digital smiley" - a cunning series of keystrokes which gave rise to the ubiquitous emoticon - is today celebrating its 25th birthday.

That's according to Carnegie Mellon University professor Scott E. Fahlman, who says that at 11:44 am on 19 September 1982, during an electronic bulletin board discussion about "the limits of online humor and how to denote comments meant to be taken lightly", he made the following fateful suggestion: "I propose the following character sequence for joke markers: :-). Read it sideways."

Fahlman explained: "I've never seen any hard evidence that the :-) sequence was in use before my original post, and I've never run into anyone who actually claims to have invented it before I did. But it's always possible that someone else had the same idea — it's a simple and obvious idea, after all."

He added in a university statement: "It has been fascinating to watch this phenomenon grow from a little message I tossed off in 10 minutes to something that has spread all around the world. I sometimes wonder how many millions of people have typed these characters, and how many have turned their heads to one side to view a smiley, in the 25 years since this all started." ®

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