diff --git a/docs/GUIDELINES.md b/docs/GUIDELINES.md
index f57daac..e47414d 100644
--- a/docs/GUIDELINES.md
+++ b/docs/GUIDELINES.md
@@ -5,7 +5,7 @@ type: guidelines
 
 ## 1. Read-only with respect to acquisition
 - The gateway subscribes. It never opens a CAN socket, TX-capable or otherwise.  
-- `obd-poller` is the single writer on the bus. Nothing here changes that.
+- `obd-poller` is the single writer to the car (OBD-II on the K-line). Nothing here changes that.
 
 ## 2. Aggregate, do not relay
 - A 500 kbps CAN bus produces far more traffic than a display can use or a USB