diff --git a/goodwe_controller/DOCS.md b/goodwe_controller/DOCS.md
index 403f4a5..fbcf5aa 100644
--- a/goodwe_controller/DOCS.md
+++ b/goodwe_controller/DOCS.md
@@ -70,6 +70,18 @@ Either way, do not build the missing shape out of template sensors. The point of
 `meter_source` is that the sign convention is derived in one tested place rather
 than in YAML nobody reviews underneath a safety input.
 
+> ⚠️ **`ha_dsmr` and `mqtt_p1` have never processed a telegram from real
+> hardware.** No meter in this installation uses either one. Both were written
+> to the assumption in `specs.md` §5.2 that a Belgian P1 exposes two unsigned
+> registers, and the meter actually fitted here does not — it is the HomeWizard
+> P1 that `ha_signed` reads. They are covered by the unit checks in `test_p1.py`
+> and by an end-to-end test against a fake Home Assistant, and nothing more.
+>
+> This is recorded because the realistic way it bites is someone debugging a
+> meter problem months from now treating those two paths as proven and looking
+> for the fault elsewhere. If you are the first person to point one at a real
+> meter, expect to find something, and please update this note when you do.
+
 | option | default | meaning |
 |---|---|---|
 | `meter_source` | `off` | `off` keeps `meter_entity`. `ha_dsmr` subscribes to the DSMR integration over the HA WebSocket; `mqtt_p1` reads a topic; `ha_signed` subscribes to one signed entity over the HA WebSocket |