+`temp-buffer-resize' means that splitting a window for displaying a
+ temporary buffer makes a new parent window provided
+ `temp-buffer-resize-mode' is enabled. Otherwise, this value is
+ handled like nil.
+
+`temp-buffer' means that splitting a window for displaying a temporary
+ buffer always makes a new parent window. Otherwise, this value is
+ handled like nil.
+
+
+`display-buffer' means that splitting a window for displaying a buffer
+ always makes a new parent window. Since temporary buffers are
+ displayed by the function `display-buffer', this value is stronger
+ than `temp-buffer'. Splitting a window for other purpose makes a
+ new parent window only if needed.
+
+t means that splitting a window always creates a new parent window. If
+ all splits behave this way, each frame's window tree is a binary
+ tree and every window but the frame's root window has exactly one
+ sibling.