diff --git a/doc/lispref/ChangeLog b/doc/lispref/ChangeLog
index 5b945c6d06e..97d6ec47ac3 100644
--- a/doc/lispref/ChangeLog
+++ b/doc/lispref/ChangeLog
@@ -1,6 +1,7 @@
 2013-11-05  Xue Fuqiao  <xfq.free@gmail.com>
 
 	* display.texi (Glyphs): Add an index for glyph code.
+	(Bidirectional Display): Add an index for UBA.
 
 2013-11-01  Jan Djärv  <jan.h.d@swipnet.se>
 
diff --git a/doc/lispref/display.texi b/doc/lispref/display.texi
index 36d8502fe9e..f0eb2379358 100644
--- a/doc/lispref/display.texi
+++ b/doc/lispref/display.texi
@@ -6388,6 +6388,7 @@ and displaying bidirectional text.
 @cindex reading order
 @cindex visual order
 @cindex unicode bidirectional algorithm
+@cindex UBA
 @cindex bidirectional reordering
   Text is stored in Emacs buffers and strings in @dfn{logical} (or
 @dfn{reading}) order, i.e., the order in which a human would read