diff --git a/source/org/jivesoftware/smack/packet/PacketExtension.java b/source/org/jivesoftware/smack/packet/PacketExtension.java
index 29746c299..40cad77c5 100644
--- a/source/org/jivesoftware/smack/packet/PacketExtension.java
+++ b/source/org/jivesoftware/smack/packet/PacketExtension.java
@@ -1,14 +1,88 @@
+/**
+ * $RCSfile$
+ * $Revision$
+ * $Date$
+ *
+ * Copyright (C) 2002-2003 Jive Software. All rights reserved.
+ * ====================================================================
+ * The Jive Software License (based on Apache Software License, Version 1.1)
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ *    if any, must include the following acknowledgment:
+ *       "This product includes software developed by
+ *        Jive Software (http://www.jivesoftware.com)."
+ *    Alternately, this acknowledgment may appear in the software itself,
+ *    if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Smack" and "Jive Software" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please
+ *    contact webmaster@jivesoftware.com.
+ *
+ * 5. Products derived from this software may not be called "Smack",
+ *    nor may "Smack" appear in their name, without prior written
+ *    permission of Jive Software.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL JIVE SOFTWARE OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ */
+
 package org.jivesoftware.smack.packet;
 
 /**
+ * Interface to represent packet extensions. A packet extension is an XML subdocument
+ * with a root element name and namespace. Packet extensions are used to provide
+ * extended functionality beyond what is in the base XMPP specification. Examples of
+ * packet extensions include message events, message properties, and extra presence data.
+ * IQ packets cannot contain packet extensions.
  *
+ * @see DefaultPacketExtension
+ * @see org.jivesoftware.smack.provider.PacketExtensionProvider
  * @author Matt Tucker
  */
 public interface PacketExtension {
 
+    /**
+     * Returns the root element name.
+     *
+     * @return the element name.
+     */
     public String getElementName();
 
+    /**
+     * Returns the root element XML namespace.
+     *
+     * @return the namespace.
+     */
     public String getNamespace();
 
+    /**
+     * Returns the XML reppresentation of the PacketExtension.
+     *
+     * @return the packet extension as XML.
+     */
     public String toXML();
 }