VMS Help DTM, DEFINE, /KEY, Command Qualifiers, /TERMINATE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

   /TERMINATE
   /NOTERMINATE (D)

   Determines whether the specified command string executes when you
   press the defined key. When you use the /NOTERMINATE qualifier,
   you must press the RETURN key to execute a command. You cannot
   specify both the /SET_STATE qualifier and the /TERMINATE qualifier
   or the /NOECHO qualifier with the /NOTERMINATE qualifier.