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

  /INTERFACE=CHARACTER_CELL (D)
  /INTERFACE=DECWINDOWS
  /INTERFACE=display-filespec

  Specifies which screen manager you want to run.

  The /INTERFACE command qualifier is optional.  By default, LSE uses the
  character-cell  screen  manager.   As  an alternative to the /INTERFACE
  qualifier, you can  define  the  logical  name  LSE$DISPLAY_MANAGER  as
  DECWINDOWS, CHARACTER_CELL, or as a screen-manager file specification.

  If you specify /INTERFACE=CHARACTER_CELL, LSE uses  the  character-cell
  screen manager, which runs in a workstation terminal emulator window or
  on a physical terminal.

  If you specify /INTERFACE=DECWINDOWS, LSE uses  the  DECwindows  screen
  manager, which creates a DECwindows window in which to run LSE.