diff --git a/db.h b/db.h
index fd4c149..ea84171 100644
--- a/db.h
+++ b/db.h
@@ -20,16 +20,24 @@ private:
   double weight;
 }
 
+//             seen nodes
+//            /          \
+// (a) banned nodes    tracked nodes
+//                    /             \
+//               tried nodes   (b) unknown nodes
+//              /           \
+//     (d) good nodes   (c) non-good nodes 
+
 class CAddrDb {
 private:
   CCriticalSection cs;
   int nId; // number of address id's
-  map<int, CAddrInfo> idToInfo; // map address id to address info
-  map<CIP, int> ipToId; // map ip to id
-  deque<int> ourId; // sequence of tracked nodes, in order we have tried connecting to them
-  set<int> unkId; // set of nodes not yet tried
-  set<int> goodId; // set of good nodes 
-  map<CIP, pair<uint32_t, uint32_t> > banned; // nodes that are banned, with their from/to ban time
+  map<int, CAddrInfo> idToInfo; // map address id to address info (b,c,d)
+  map<CIP, int> ipToId; // map ip to id (b,c,d)
+  deque<int> ourId; // sequence of tried nodes, in order we have tried connecting to them (c,d)
+  set<int> unkId; // set of nodes not yet tried (b)
+  set<int> goodId; // set of good nodes  (d)
+  map<CIP, pair<uint32_t, uint32_t> > banned; // nodes that are banned, with their from/to ban time (a)
   
 public:
   void Add(const CAddress &addr);