[groff] 10/25: doc/groff.texi: Note significant historical point.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 6f6d40cc4d0548f53013f20c1446667ba6c6ab1f
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Tue Mar 29 00:23:57 2022 +1100

    doc/groff.texi: Note significant historical point.
    
    "One of the most amusing and unexpected consequences of phototypesetting
    was the Unix standard error file (!).   After phototypesetting, you had
    to take a long wide strip of paper and feed it carefully into a smelly,
    icky machine which eventually (several minutes later) spat out the paper
    with the printing visible.
    
    One afternoon several of us had the same experience -- typesetting
    something, feeding the paper through the developer, only to find a
    single, beautifully typeset line: "cannot open file foobar"   The
    grumbles were loud enough and in the presence of the right people, and a
    couple of days later the standard error file was born..." -- Steven C.
    Johnson
---
 doc/groff.texi | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/doc/groff.texi b/doc/groff.texi
index b816d814..d01abafe 100644
--- a/doc/groff.texi
+++ b/doc/groff.texi
@@ -884,7 +884,11 @@ streams, respectively.  Diagnostic messages from the GNU 
@code{troff}
 formatter and other programs are examples of the latter, but the
 formatter can also be directed to write user-specified messages to the
 standard error stream.  The notation then serves to distinguish the
-output stream and does not necessarily mean that an error has occurred.
+output stream and does not necessarily mean that an error has
+occurred.@footnote{Unix and related operating systems distinguish
+standard output and standard error streams @emph{because} of
+@code{troff}:@:
+@uref{https://minnie.tuhs.org/pipermail/tuhs/2013-December/006113.html}.}
 
 @Example
 $ echo "Twelve o'clock and" | groff -Tascii | sed '/^$/d'