/sys$common/syshlp/helplib.hlb FORTRAN, Character Sets, Printable Characters  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Printable characters include the tab character (09 hex), those
  ASCII characters with codes in the range 20(hex) through 7E(hex),
  and those characters in the DEC Multinational Extension to the
  ASCII Character Set with codes in the range A1(hex) through
  FE(hex).

  Note that printable characters that are not in the Fortran
  character set (see Character_Set subtopic FORTRAN) can only appear
  in comments and character and Hollerith constants.