The REAL type denotes single-precision real  values.   The  REAL
  type is synonymous with the SINGLE type.  The largest REAL value
  is denoted by MAXREAL.  The smallest REAL value  is  denoted  by
  MINREAL.  EPSREAL denotes the result of subtracting 1.0 from the
  smallest REAL value that is greater than 1.0.

  Example:  2.4
            2.3e2        {exponential notation}

  On OpenVMS VAX systems, REAL uses  the  F_Floating  format.   On
  OpenVMS  Alpha  systems,  REAL  can  take  one  of  two formats:
  F_Floating and IEEE S_Floating.  To specify a format, use either
  the FLOAT attribute or the /FLOAT command line qualifier.

  The default format on OpenVMS VAX and OpenVMS Alpha  systems  is
  F_Floating.   The  default format on OpenVMS I64 systems is IEEE
  S_Floating.  On OpenVMS I64 systems, F_Floating is supported  by
  converting  to/from  IEEE  S_Floating  for  all  floating  point
  operations.