/sys$common/syshlp/helplib.hlb FORTRAN, Logical Names, FOR$READ  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  If defined during execution, 'FOR$READ' is used instead of
  'SYS$INPUT' as the file specification for the implicit Fortran
  logical unit used for READ statements that specify * or omit the
  unit number.