17.4.2 %VARIANT Directive
  The %VARIANT directive is a built-in lexical function that
  returns an integer. The value of this returned integer is
  determined by:

  .
        The SET VARIANT command when a program is com-
        piled in the BASIC environment
  .
        The /VARIANT qualifier when a program is compiled
        from the system command level or from within the
        BASIC environment

  The %VARIANT function returns the variant value set with
  either of these methods.

  The default value for the %VARIANT function is zero. See
  Section 17.4.5 for an example of controlling compilation with
  %VARIANT.