Richtext : why an US-ASCII formatting command ?

   Date:         Tue, 17 Dec 91 08:59:52 +0100
   From: "Alain FONTAINE (Postmaster - UCL)" 
<fontaine(_at_)sri(_dot_)ucl(_dot_)ac(_dot_)be>

   I really don't see why an 'US-ASCII' formatting command is defined.

        ...

   it follows that 'us-ascii' can only be used to switch from us-ascii to
   us-ascii !!!!

No.  It can also be used to put a small amount of US-ASCII in the
midst of other things.  For example, if I am writing something in
Norwegian, which (I'm pretty sure I recall) doesn't have the "{"
character, and I happen to want one I can just switch to US-ASCII and
then back out.  This doesn't lose any other context that might exist
at the time (e.g. Bold).  The TeX macro packages all learned early on
that although it's not often used, the ability to switch to the
default *is* needed...

            __
  /|  /|  /|  \         Michael A. Patton, Network Manager
 / | / | /_|__/         Laboratory for Computer Science
/  |/  |/  |atton       Massachusetts Institute of Technology