VMS Help EDIT, /SUM, Qualifiers, /LISTING  *Conan The Librarian (sorry for the slow response - running on an old VAX)

   /LISTING[=file-spec]

   Determines whether a sequence-numbered listing file, showing the
   original and inserted lines and an audit trail, is produced during
   the editing process. If you do not include a file specification,
   the listing file takes the same name as the input file, with a file
   type of LIS. By default, no listing file is produced.