diff --git a/include/libtorrent/alert_manager.hpp b/include/libtorrent/alert_manager.hpp
index 03ff775bd..bda17222e 100644
--- a/include/libtorrent/alert_manager.hpp
+++ b/include/libtorrent/alert_manager.hpp
@@ -183,7 +183,8 @@ namespace libtorrent {
 
 		// this is either 0 or 1, it indicates which m_alerts and m_allocations
 		// the alert_manager is allowed to use right now. This is swapped when
-		// the client calls get_all(), at which point 
+		// the client calls get_all(), at which point all of the alert objects
+		// passed to the client will be owned by libtorrent again, and reset.
 		int m_generation;
 
 		// this is where all alerts are queued up. There are two heterogenous
diff --git a/include/libtorrent/aux_/session_impl.hpp b/include/libtorrent/aux_/session_impl.hpp
index 40f3576ec..9310b3a9d 100644
--- a/include/libtorrent/aux_/session_impl.hpp
+++ b/include/libtorrent/aux_/session_impl.hpp
@@ -778,8 +778,6 @@ namespace libtorrent
 			// to clear the undead peers
 			boost::optional<io_service::work> m_work;
 
-			typedef std::list<boost::shared_ptr<torrent> > check_queue_t;
-
 			// this maps sockets to their peer_connection
 			// object. It is the complete list of all connected
 			// peers.
@@ -1140,6 +1138,7 @@ namespace libtorrent
 			external_ip m_external_ip;
 
 #ifndef TORRENT_DISABLE_EXTENSIONS
+			// this is a list to allow extensions to potentially remove themselves.
 			typedef std::list<boost::shared_ptr<plugin> > ses_extension_list_t;
 			ses_extension_list_t m_ses_extensions;
 #endif
diff --git a/src/session_impl.cpp b/src/session_impl.cpp
index 2eaab144c..1f042f45c 100644
--- a/src/session_impl.cpp
+++ b/src/session_impl.cpp
@@ -886,7 +886,7 @@ namespace aux {
 		m_alerts.add_extension(ext);
 		ext->added(this);
 	}
-#endif
+#endif // TORRENT_DISABLE_EXTENSIONS
 
 #ifndef TORRENT_NO_DEPRECATE
 	feed_handle session_impl::add_feed(feed_settings const& sett)
diff --git a/src/ut_metadata.cpp b/src/ut_metadata.cpp
index a8ae389bc..845c38b41 100644
--- a/src/ut_metadata.cpp
+++ b/src/ut_metadata.cpp
@@ -125,7 +125,7 @@ namespace libtorrent { namespace
 
 		virtual boost::shared_ptr<peer_plugin> new_connection(
 			peer_connection* pc);
-		
+
 		int get_metadata_size() const
 		{
 			TORRENT_ASSERT(m_metadata_size > 0);
diff --git a/src/web_peer_connection.cpp b/src/web_peer_connection.cpp
index a57ea6d11..f157ca1bd 100644
--- a/src/web_peer_connection.cpp
+++ b/src/web_peer_connection.cpp
@@ -662,7 +662,7 @@ void web_peer_connection::on_receive(error_code const& error
 #endif
 					return;
 				}
-				
+
 				bool single_file_request = false;
 				if (!m_path.empty() && m_path[m_path.size() - 1] != '/')
 					single_file_request = true;