src/share/classes/java/lang/Character.java

*** 2569,2578 ****
--- 2569,2582 ----
       * should generally be used in preference to the constructor
       * {@link #Character(char)}, as this method is likely to yield
       * significantly better space and time performance by caching
       * frequently requested values.
       *
+      * This method will always cache values in the range '\u0000'
+      * to '\u007f'", inclusive, and may cache other values outside
+      * of this range.
+      *
       * @param  c a char value.
       * @return a <tt>Character</tt> instance representing <tt>c</tt>.
       * @since  1.5
       */
      public static Character valueOf(char c) {