alt

alt /awlt/  1. n. The alt shift key on an IBM PC or
   {clone} keyboard; see {bucky bits}, sense 2 (though typical
   PC usage does not simply set the 0200 bit).  2. n. The `clover'
   or `Command' key on a Macintosh; use of this term usually reveals
   that the speaker hacked PCs before coming to the Mac (see also
   {feature key}).  Some Mac hackers, confusingly, reserve `alt'
   for the Option key (and it is so labeled on some Mac II keyboards).
   3. n.obs.  [PDP-10; often capitalized to ALT] Alternate name for
   the ASCII ESC character (ASCII 0011011), after the keycap labeling
   on some older terminals; also `altmode' (/awlt'mohd/).  This
   character was almost never pronounced `escape' on an ITS system,
   in {TECO}, or under TOPS-10 -- always alt, as in "Type alt alt
   to end a TECO command" or "alt-U onto the system" (for "log
   onto the [ITS] system").  This usage probably arose because alt is
   more convenient to say than `escape', especially when followed by
   another alt or a character (or another alt *and* a character,
   for that matter).  3. The alt hierarchy on Usenet, the tree of
   newsgroups created by users without a formal vote and approval
   procedure.  There is a myth, not entirely, implausible, that
   alt is acronymic for "anarchists, lunatics, and terrorists";
   but in fact it is simply short for "alternative".