diff --git a/model/sync-data-buffer.h b/model/sync-data-buffer.h
index dd6dbb8..09e15f4 100644
--- a/model/sync-data-buffer.h
+++ b/model/sync-data-buffer.h
@@ -95,17 +95,33 @@
 	virtual void setBufferAndLength(const unsigned char *buffer, size_t len)
 	{m_dataBuffer->setBufferAndLength(buffer, len); }
 
+	/**
+	 * @brief convert from FullState to SyncDataBuffer
+	 */
 	SyncDataBuffer &operator<<(FullState &fs);
+
+	/**
+	 * @brief convert from DiffState to SyncDataBuffer
+	 */
 	SyncDataBuffer &operator<<(DiffState &ds);
 
+	/**
+	 * @brief convert from SyncDataBuffer to FullState, throws
+	 * SyncDataBufferConvertException if convert fails
+	 */
 	SyncDataBuffer &operator>>(FullState &fs);
+
+	/**
+	 * @brief convert from SyncDataBuffer to DiffState, throws
+	 * SyncDataBufferConvertException if convert fails
+	 */
 	SyncDataBuffer &operator>>(DiffState &ds);
 
 private:
 	boost::shared_ptr<DataBuffer> m_dataBuffer;
 };
 
-struct SyncDataBufferConvertError : virtual boost::exception {};
+struct SyncDataBufferConvertException : virtual boost::exception {};
 
 } // Sync
 
diff --git a/model/sync-interest-table.h b/model/sync-interest-table.h
index 4993cd4..609436d 100644
--- a/model/sync-interest-table.h
+++ b/model/sync-interest-table.h
@@ -23,7 +23,7 @@
 #ifndef SYNC_STATE_H
 #define SYNC_STATE_H
 #include <string>
-#include <boost/unordered_map.hpp>
+#include <boost/unordered_set.hpp>
 
 /**
  * \defgroup sync SYNC protocol
@@ -39,10 +39,17 @@
 class SyncInterestTable
 {
 private:
-	boost::unordered_map<std::string, std::string> m_table;
+	boost::unordered_set<std::string> m_table;
 public:
+	/**
+	 * @brief Insert an interest
+	 */
 	bool insert(std::string interest);
-	boost::unordered_map<std::string, std::string> fetchAll();
+
+	/**
+	 * @brief fetch all Interests and clear the table
+	 */
+	boost::unordered_set<std::string> fetchAll();
 
 };