SET SELECTION GRAB SELECTION   (default in DECwindows)
  Enables grabbing the DECwindows primary selection only when you select
  text. This is the default setting in the DECwindows interface.
  Usage notes:
  o  This command is valid only with the DECwindows interface, not on
     DECterm or character-cell terminals.
  o  The primary selection is the selection that can be shared among
     DECwindows applications without having to use the clipboard. In EVE,
     you create a primary selection by using SELECT or BOX SELECT, or by
     dragging or clicking M1. (A found range is never the primary
     selection).
  o  When you create a primary selection in another application, EVE loses
     the primary selection. EVE saves the current selection and removes the
     highlighting from the selected text.
  o  If SET SELECTION GRAB SELECTION is in effect, then EVE grabs the
     primary selection only when you select text. To restore the saved
     selection, press CTRL/SHIFT/SELECT. The saved selection will be
     restored correctly only if the current position is the same as when EVE
     lost the primary selection.
  o  The alternate behavior is to grab the primary selection when you give
     EVE the input focus. See help on SET SELECTION GRAB FOCUS.
  Related topics:
     Mouse    Ranges And Boxes    SET SELECTION GRAB FOCUS