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

   /INTERFACE=interface

   Specifies that Digital Test Manager is to run in the character
   cell (terminal) or DECwindows environment. The options for this
   qualifier are CHARACTER_CELL (the default) and DECWINDOWS.