molly-guard

from Jargon File (4.4.4, 14 Aug 2003)

molly-guard
 /mol'ee.gard/, n.

   [University of Illinois] A shield to prevent tripping of some {Big Red
   Switch} by clumsy or ignorant hands. Originally used of the plexiglass
   covers improvised for the BRS on an IBM 4341 after a programmer's
   toddler daughter (named Molly) frobbed it twice in one day. Later
   generalized to covers over stop/reset switches on disk drives and
   networking equipment. In hardware catalogues, you'll see the much less
   interesting description "guarded button".

from The Free On-line Dictionary of Computing (8 July 2008)

molly-guard

   /mol'ee-gard/ [University of Illinois] A shield to prevent
   tripping of some {Big Red Switch} by clumsy or ignorant hands.
   Originally used of the plexiglass covers improvised for the
   BRS on an IBM 4341 after a programmer's toddler daughter
   (named Molly) frobbed it twice in one day.  Later generalised
   to covers over stop/reset switches on disk drives and
   networking equipment.

   [{Jargon File}]