Twenty Thirty years ago today*, a computer scientist at Carnegie Mellon posted this to a message board:

19-Sep-82 11:44 Scott E. Fahlman :-)
From: Scott E. Fahlman

I propose that the following character sequence for joke markers:


Read it sideways. Actually, it is probably more economical to mark
things that are NOT jokes, given current trends. For this, use


: - |

* I'm no mathologist, but Slog's trusty commenters are. Thanks, guys—and expect to see this correction in our annual regrets issue.