The Jargon File (version 4.4.7, 29 Dec 2003):
Vulcan nerve pinch
 n.
    [from the old Star Trek TV series via Commodore Amiga hackers] The keyboard
    combination that forces a soft-boot or jump to ROM monitor (on machines
    that support such a feature). On Amigas this is --
    ; on PC clones this is Ctrl-Alt-Del; on Suns, L1-A; on
    Macintoshes, it is - or --! On IRIX,
    , which kills and restarts the X
    server, is sometimes called a vulcan nerve pinch. Also called three-finger
    salute and Vulcan death grip. At shops with a lot of Microsoft Windows
    machines, this is often called the Microsoft Maneuver because of the
    distressing frequency with which Microsoft's unreliable software requires
    it. Compare quadruple bucky.
The Free On-line Dictionary of Computing (30 December 2018):
Vulcan nerve pinch
three-finger salute
    (Or "three-finger salute", Vulcan death grip; from
   the old "Star Trek" TV series via Commodore Amiga
   hackers) The keyboard combination that forces a soft boot
   or jump to ROM monitor (on machines that support such a
   feature).
   On an Amiga this is done with Ctrl/Right Amiga/Left Amiga; on
   IBM PCs and many microcomputers it is Ctrl/Alt/Del; on
   Suns, L1-A; on some Macintoshes, it is -!  Silicon Graphics users are obviously the most
   dextrous however, as these machines use the five-finger
   combination: Left Shift/Left Ctrl/Left Alt/Keypad Divide/F12.
   Compare quadruple bucky.
   [Jargon File]
   (2000-04-04)