> Turns out he’d been taught in typing class that l (lowercase L) could be used for 1 and carried that into computing. A good way to keep them busy would have

> Turns out he’d been taught in typing class that l (lowercase L) could be used for 1 and carried that into computing. A good way to keep them busy would have been to demand they type an exclamation point. (Hint: Backspace-and-overstrike a period with a single quote.)