-You can also enable auto-raise (raising automatically when a frame is
-selected) or auto-lower (lowering automatically when it is deselected)
-for any frame using frame parameters. @xref{Management Parameters}.
+ On window systems, you can also enable auto-raising (on frame
+selection) or auto-lowering (on frame deselection) using frame
+parameters. @xref{Management Parameters}.
+
+@cindex top frame
+ The concept of raising and lowering frames also applies to text
+terminal frames. On each text terminal, only the top frame is
+displayed at any one time.
+
+@defun tty-top-frame terminal
+This function returns the top frame on @var{terminal}. @var{terminal}
+should be a terminal object, a frame (meaning that frame's terminal),
+or @code{nil} (meaning the selected frame's terminal). If it does not
+refer to a text terminal, the return value is @code{nil}.
+@end defun