diff --git a/doc/devel/UML/iso_tree.violet b/doc/devel/UML/iso_tree.violet
index 85c7237..a3fa226 100644
--- a/doc/devel/UML/iso_tree.violet
+++ b/doc/devel/UML/iso_tree.violet
@@ -32,7 +32,8 @@ biblio_file_id : char*</string>
    <object id="ClassNode1" class="com.horstmann.violet.ClassNode"> 
     <void property="attributes"> 
      <void property="text"> 
-      <string>sort_weight : int</string> 
+      <string>sort_weight : int
+block : uint32_t</string> 
      </void> 
     </void> 
     <void property="name"> 
@@ -426,6 +427,23 @@ SourceFile</string>
     </void> 
    </object> 
   </void> 
+  <void method="addNode"> 
+   <object id="NoteNode2" class="com.horstmann.violet.NoteNode"> 
+    <void property="text"> 
+     <void property="text"> 
+      <string>For files, we need to know whethe they come
+from a previous session. That&apos;s the purpose of
+the block field</string> 
+     </void> 
+    </void> 
+   </object> 
+   <object class="java.awt.geom.Point2D$Double"> 
+    <void method="setLocation"> 
+     <double>818.829652614022</double> 
+     <double>414.36457377531684</double> 
+    </void> 
+   </object> 
+  </void> 
   <void method="connect"> 
    <object class="com.horstmann.violet.ClassRelationshipEdge"> 
     <void property="bentStyle"> 
@@ -721,5 +739,10 @@ SourceFile</string>
    <object idref="ClassNode1"/> 
    <object idref="InterfaceNode3"/> 
   </void> 
+  <void method="connect"> 
+   <object class="com.horstmann.violet.NoteEdge"/> 
+   <object idref="ClassNode1"/> 
+   <object idref="NoteNode2"/> 
+  </void> 
  </object> 
 </java>