The C_STR_T  predefined  type  is  provided  to  interface  with
  routines   written  in  the  C  language  using  null-terminated
  strings.  C_STR_T behaves like a normal pointer type in that you
  can  assign  NIL  into it and the optional pointer checking code
  will check for dereferencing of a NIL pointer.   The  individual
  characters can be used by dereferencing the pointer and using an
  array index.  No bounds checking will be performed even if array
  bounds checking is enabled.

  You cannot dereference a C_STR_T pointer without also indexing a
  single   character.    If   you   want   to   access  an  entire
  null-terminated string, see the PAS_STR function.