CHARACTER_DEFINITIONS

  Lists all the character set description files (charmaps) in the
  public directory defined by the logical name SYS$I18N_LOCALE.  A
  charmap defines symbolic names and values of characters in a coded
  character set.  Charmaps are used by the LOCALE COMPILE command
  when compiling a locale.  A charmap file has the file type .CMAP.

  Format:

       LOCALE SHOW CHARACTER_DEFINITIONS