Index: src/java/org/apache/lucene/search/IndexSearcher.java
===================================================================
--- src/java/org/apache/lucene/search/IndexSearcher.java	(revision 798103)
+++ src/java/org/apache/lucene/search/IndexSearcher.java	(working copy)
@@ -36,6 +36,14 @@
  * 
  * <p>Note that you can only access Hits from an IndexSearcher as long as it is
  * not yet closed, otherwise an IOException will be thrown. 
+ *
+ * <a name="thread-safety"></a><p><b>NOTE</b>: {@link
+ * <code>IndexSearcher</code>} instances are completely
+ * thread safe, meaning multiple threads can call any of its
+ * methods, concurrently.  If your application requires
+ * external synchronization, you should <b>not</b> use the
+ * <code>IndexSearcher</code> instance for synchronization;
+ * use a private <code>Object</code> instead. </p>
  */
 public class IndexSearcher extends Searcher {
   IndexReader reader;
Index: src/java/org/apache/lucene/index/IndexReader.java
===================================================================
--- src/java/org/apache/lucene/index/IndexReader.java	(revision 798096)
+++ src/java/org/apache/lucene/index/IndexReader.java	(working copy)
@@ -67,6 +67,14 @@
  if you want to make changes with the resulting IndexReader.
  </p>
 
+ <a name="thread-safety"></a><p><b>NOTE</b>: {@link
+ <code>IndexReader</code>} instances are completely thread
+ safe, meaning multiple threads can call any of its methods,
+ concurrently.  If your application requires external
+ synchronization, you should <b>not</b> use the
+ <code>IndexReader</code> instance for synchronization; use
+ a private <code>Object</code> instead. </p>
+
  @version $Id$
 */
 public abstract class IndexReader implements Cloneable {