diff --git a/tmux.1 b/tmux.1
index f5d7fe5c..23fd6833 100644
--- a/tmux.1
+++ b/tmux.1
@@ -1,4 +1,4 @@
-.\" $Id: tmux.1,v 1.293 2011-01-21 23:46:50 tcunha Exp $
+.\" $Id: tmux.1,v 1.294 2011-01-21 23:53:45 tcunha Exp $
 .\"
 .\" Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
 .\"
@@ -2157,8 +2157,11 @@ may use the terminal alternate screen feature, which allows the
 and
 .Em rmcup
 .Xr terminfo 5
-capabilities to be issued to preserve the existing window content on start and
-restore it on exit.
+capabilities.
+The alternate screen feature preserves the contents of the window when an
+interactive application starts and restores it on exit, so that any output
+visible before the application starts reappears unchanged after it exits.
+The default is on.
 .Pp
 .It Xo Ic automatic-rename
 .Op Ic on | off