The Free On-line Dictionary of Computing (19 January 2023):

drool-proof paper

    Documentation that has been obsessively dumbed
   down, to the point where only a cretin could bear to read
   it, is said to have succumbed to the "drool-proof paper
   syndrome" or to have been "written on drool-proof paper".  For
   example, this is an actual quote from Apple Computer's
   LaserWriter manual: "Do not expose your LaserWriter to open
   fire or flame."

   [Jargon File]

   (1997-06-23)


The Jargon File (version 4.4.7, 29 Dec 2003):

drool-proof paper
 n.

    Documentation that has been obsessively dumbed down, to the point where
    only a cretin could bear to read it, is said to have succumbed to the
    ‘drool-proof paper syndrome’ or to have been ‘written on drool-proof
    paper’. For example, this is an actual quote from Apple's LaserWriter
    manual: “Do not expose your LaserWriter to open fire or flame.” The SGI
    Indy manual included the line “[Do not] dangle the mouse by the cord or
    throw it at coworkers.”