diff -r a65826af2aa4 -r 701d0765f75f jdk/src/share/classes/javax/sql/rowset/serial/SerialRef.java
--- a/jdk/src/share/classes/javax/sql/rowset/serial/SerialRef.java	Thu Dec 13 08:11:38 2012 +0800
+++ b/jdk/src/share/classes/javax/sql/rowset/serial/SerialRef.java	Wed Dec 12 20:57:45 2012 -0500
@@ -36,6 +36,13 @@
  * The <code>SerialRef</code> class provides a constructor  for
  * creating a <code>SerialRef</code> instance from a <code>Ref</code>
  * object and provides methods for getting and setting the <code>Ref</code> object.
+ *
+ * <h4> Thread safety </h4>
+ *
+ * A SerialRef is not safe for use by multiple concurrent threads.  If a
+ * SerialRef is to be used by more than one thread then access to the SerialRef
+ * should be controlled by appropriate synchronization.
+ *
  */
 public class SerialRef implements Ref, Serializable, Cloneable {