V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

ARG
       Alternate Reality Game


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

arg
 /arg/, n.

    Abbreviation for ?argument? (to a function), used so often as to have
    become a new word (like ?piano? from ?pianoforte?). ?The sine function
    takes 1 arg, but the arc-tangent function can take either 1 or 2 args.?
    Compare param, parm, var.


The Free On-line Dictionary of Computing (30 December 2018):

argument
arg

    (Or "arg") A value or reference passed to a
   function, procedure, subroutine, command or program, by
   the caller.  For example, in the function definition

   	square(x) = x * x

   x is the formal argument or "parameter", and in the call

   	y = square(3+4)

   3+4 is the actual argument.  This will execute the function
   square with x having the value 7 and return the result 49.

   There are many different conventions for passing arguments to
   functions and procedures including call-by-value,
   call-by-name, call-by-reference, call-by-need.  These
   affect whether the value of the argument is computed by the
   caller or the callee (the function) and whether the callee can
   modify the value of the argument as seen by the caller (if it
   is a variable).

   Arguments to functions are usually, following mathematical
   notation, written in parentheses after the function name,
   separated by commas (but see curried function).  Arguments
   to a program are usually given after the command name,
   separated by spaces, e.g.:

   	cat myfile yourfile hisfile

   Here "cat" is the command and "myfile", "yourfile", and
   "hisfile" are the arguments.

   (2006-05-27)