Index: src/java/org/apache/lucene/index/IndexWriter.java
===================================================================
--- src/java/org/apache/lucene/index/IndexWriter.java	(revision 795841)
+++ src/java/org/apache/lucene/index/IndexWriter.java	(working copy)
@@ -186,6 +186,13 @@
   last commit.  If you opened the writer with autoCommit
   false you can also just call {@link #rollback()}
   directly.</p>
+  <a name="thread-safety"></a><p><b>NOTE</b>: 
+  {@link IndexWriter} instances are designed to be thread safe
+  and can therefore be shared among different threads. In fact
+  it is <b>not</b> recommended to synchronize {@link IndexWriter}
+  access or use an {@link IndexWriter} instance as an synchronization
+  object. (See also {@link IndexWriter#addIndexesNoOptimize(Directory[])})
+  </p>
 */
 
 /*