Holy cow, I wrote a book!
In e-mail from Microsoft employees, you may find a stray J
like this one at the end of a message from Rico Mariani.
Some of you might see it; others might not.
What's the deal with the J?
The J started out its life as a smiley-face.
font puts a smiley face where the letter J goes.
Here, let me try:
results in J.
As the message travels from machine to machine, the font formatting
may get lost or mangled, resulting in the letter J appearing
when a smiley face was intended.
(Note that this is not the same as the smiling face incorporated
into Unicode as U+263A, which looks like this: ☺.
Some of you might see it; others might not.)
I recall a story (possibly apocryphal) of somebody who regularly exchanged
a lot of e-mail with Microsoft employees and who as a result
started signing their own messages with a J,
figuring this was some sort of Microsoft slang.
The Microsoft employees who got the J-messages scratched their heads
until they were able to figure out how their correspondent arrived
at this fabulous deduction.
And now, the mysterious J has come full circle,
because some people use it ironically,
intentionally just writing a J without setting the font,
in the same way people making fun of
"leet" writing may
"accidentally" type "1"s (or even more absurdly,
the word "one") into a row of exclamation points.