Improve documentation of "C-x 8 RET".

mule.texi (Input Methods): Mention "C-x 8 RET" and add a
 cross-reference to "Inserting Text".
 basic.texi (Inserting Text): Add an index entry for "C-x 8 RET".
 Mention completion provided by `ucs-insert'.

doc/emacs/ChangeLog

@@ -1,3 +1,11 @@
+2010-03-30  Eli Zaretskii  <eliz@gnu.org>
+
+	* mule.texi (Input Methods): Mention "C-x 8 RET" and add a
+	cross-reference to "Inserting Text".
+
+	* basic.texi (Inserting Text): Add an index entry for "C-x 8 RET".
+	Mention completion provided by `ucs-insert'.
+
 2010-03-28  Chong Yidong  <cyd@stupidchicken.com>
 
 	* sending.texi (Sending Mail): Note variables that may need

doc/emacs/basic.texi

@@ -100,13 +100,15 @@ character code, just like digits.
 character to insert (@pxref{Arguments}).
 
 @findex ucs-insert
+@kindex C-x 8 RET
 @cindex Unicode
   Instead of @kbd{C-q}, you can use @kbd{C-x 8 @key{RET}}
 (@code{ucs-insert}) to insert a character based on its Unicode name or
 code-point.  This commands prompts for a character to insert, using
 the minibuffer; you can specify the character using either (i) the
 character's name in the Unicode standard, or (ii) the character's
-code-point in the Unicode standard.
+code-point in the Unicode standard.  If you specify the character's
+name, the command provides completion.
 
 @node Moving Point
 @section Changing the Location of Point

doc/emacs/mule.texi

@@ -533,6 +533,11 @@ most input methods---some disable this feature).  If
 possible characters to type next is displayed in the echo area (but
 not when you are in the minibuffer).
 
+  Another facility for typing characters not on your keyboard is by
+using the @kbd{C-x 8 @key{RET}} (@code{ucs-insert}) to insert a single
+character based on its Unicode name or code-point; see @ref{Inserting
+Text}.
+
 @node Select Input Method
 @section Selecting an Input Method