Library /sys$common/syshlp/basichelp.hlb Compile time errors, ILLCHAEXT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  ERROR - The external  symbol  in  an  EXTERNAL  FUNCTION  or  CONSTANT
  declaration   contains  an  invalid  character.   Remove  the  invalid
  character.  External names on PDP-11 systems  can  use  only  printing
  ASCII characters:  ASCII values in the range 32 to 126, inclusive.