VMS Help DTM, SHOW, PROLOGUE, Command Qualifier, /OUTPUT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

   /OUTPUT[=file-specification]

   Sends the requested information to the specified file. If you
   specify the file name but omit the file type, the file type
   defaults to .LIS. The output is sent to SYS$OUTPUT.