diff --git a/firmware/controllers/electronic_throttle.cpp b/firmware/controllers/electronic_throttle.cpp
index fc93b10183..9105616746 100644
--- a/firmware/controllers/electronic_throttle.cpp
+++ b/firmware/controllers/electronic_throttle.cpp
@@ -4,6 +4,13 @@
  *
  * todo: make this more universal if/when we get other hardware options
  *
+ * Jan 2017 status:
+ *  PID implementation tested on a bench only
+ *  it is believed that more than just PID would be needed, as is this is probably
+ *  not usable on a real vehicle. Needs to be tested :)
+ *
+ * http://rusefi.com/forum/viewtopic.php?f=5&t=592
+ *
  * @date Dec 7, 2013
  * @author Andrey Belomutskiy, (c) 2012-2017
  *
diff --git a/firmware/hw_layer/HIP9011.cpp b/firmware/hw_layer/HIP9011.cpp
index a6ebf03fb3..f9cd1c3d18 100644
--- a/firmware/hw_layer/HIP9011.cpp
+++ b/firmware/hw_layer/HIP9011.cpp
@@ -8,6 +8,9 @@
  *  3) engine control does not yet react to knock since very little actual testing - no engine runs with proven knock yet
  *
  *
+ * http://rusefi.com/forum/viewtopic.php?f=4&t=400
+ * http://rusefi.com/forum/viewtopic.php?f=5&t=778
+ *
  *	pin1	VDD
  *	pin2	GND
  *