Additional_Character_Sets

   With ODS-5, RMS supports access to files and directories whose
   names contain arbitrary 8-bit characters, except for the C0
   control set (hex 00 through 1F) and the following characters:

      Double quotation marks (")
      Asterisk (*)
      Backslash (\)
      Colon (:)
      Left and right angle brackets (< >)
      Slash (/)
      Question mark (?)
      Vertical bar (|)

   Note that this explicitly includes both the C1 character set (hex
   80-9F) as well as graphical and other characters between 9F and
   FF. This allows the entire ISO Latin-1 character set (with the
   7-bit character exclusions noted above) and any defined Unicode
   character.