/sys$common/syshlp/helplib.hlb PASCAL, /DIAGNOSTICS[=file-spec] D=/NODIAGNOSTICS  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  /NODIAGNOSTICS

  Creates a  file  containing  compiler  messages  and  diagnostic
  information.  If the file-spec is omitted, the default file name
  is the same as the source program; the default file type is DIA.

  The diagnostics file is reserved for use  with  OpenVMS  layered
  products,    such    as,   but   not   limited   to,   the   DEC
  Language-Sensitive Editor.