From: Guy Steele <gls@think.com>
Date: Fri, 14 Jun 91 14:10:40 EDT
To: info-its@life.ai.mit.edu, info-its@mc.lcs.mit.edu
Subject: Flag Day

Today is Flag Day.  As we celebrate this patriotic holiday, let us pause
for a moment of reflection.
    It is also the 25th anniversary of the original "Flag Day" on Multics.
On June 14, 1966, Multics switched over from old ASCII to new ASCII (ever
wonder why old-timers still call the '^' character "uparrow"?).  Naturally,
this wreaked all the havoc one could expect, and then some.  From this
incident the term "flag day" passed into hacker slang as a term for a
change that is neither forward-compatible nor backward-compatible (so old
programs don't work under the new system and new programs don't work under
the old one) and is both costly to make and costly to undo.
    Let us therefore pause for a moment of confusion and remember the good
old days when hackers were hackers, circumflex was uparrow, and lowercase
was for wimps.

--Guy