/sys$common/syshlp/helplib.hlb DTM, SPAWN, Command Qualifiers, /OUTPUT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

   /OUTPUT=file-specification

   Specifies the output file to which the output of the SPAWN
   operation is to be written. If you specify the /NOWAIT qualifier,
   use the /OUTPUT qualifier to specify an output other than
   SYS$OUTPUT to prevent your terminal from being used by both
   processes simultaneously. The default is to direct output to the
   current SYS$OUTPUT device.