Index: index.html
===================================================================
--- index.html	(revision 30686)
+++ index.html	(revision 30687)
@@ -11,14 +11,23 @@
 <h2> Table of Contents </h2>
 <p>
 <ul class="toc">
-	<li><a href="01_intro/index.html">   1. Introduction </a>
-	<li><a href="02_model/index.html">   2. Model of the world </a>
-	<li><a href="03_data/index.html">    3. Where data is stored </a>
-	<li><a href="04_invoc/index.html">   4. Program Invocation </a>
-	<li><a href="05_ui/index.html">      5. Graphical and Batch User Interfaces </a>
-	<li><a href="06_feature/index.html"> 6. Feature plugins </a>
-	<li><a href="07_io/index.html">      7. File formats </a>
-	<li><a href="08_util/index.html">    8. Utilities </a>
-	<li><a href="09_appendix/index.html">9. Appendix </a>
+	<li> Volume 1: Core functionality
+	<ul class="toc">
+		<li><a href="01_intro/index.html">   1. Introduction </a>
+		<li><a href="02_model/index.html">   2. Model of the world </a>
+		<li><a href="03_data/index.html">    3. Where data is stored </a>
+		<li><a href="04_invoc/index.html">   4. Program Invocation </a>
+		<li><a href="05_ui/index.html">      5. Graphical and Batch User Interfaces </a>
+	</ul>
+	<li> Volume 2: Plugins and utilities
+	<ul class="toc">
+		<li><a href="06_feature/index.html"> 6. Feature plugins </a>
+		<li><a href="07_io/index.html">      7. File formats </a>
+		<li><a href="08_util/index.html">    8. Utilities </a>
+	</ul>
+	<li> Volume 3: Appendix and misc
+	<ul class="toc">
+		<li><a href="09_appendix/index.html">9. Appendix </a>
+	</ul>
 </ul>