Printable_Characters

 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).

 Printable characters that are not in the Fortran 95/90 character
 set (see CHAR FORTRAN_90 in online Help) can only appear in
 comments, character constants, Hollerith constants, character
 string edit descriptors, and input/output records.