diff --git a/CAN.md b/CAN.md
index 7c105e4b..c30a8e37 100644
--- a/CAN.md
+++ b/CAN.md
@@ -1,5 +1,7 @@
 # Overview of CAN usage and IDs used by rusEFI
 
+Note: We support OBD2 pretty much exclusively for gauges/dashes/apps/etc, not real diagnosis!
+
 * rusEFI WBO two way communication 0xEF50000 0x190
 * rusEFI WBO bootloader
 * rusEFI gauge broadcast 0x200 default base see [DBC](https://github.com/rusefi/rusefi/blob/master/firmware/controllers/can/rusEFI_CAN_verbose.dbc)