diff --git a/combo/src/main/java/info/nightscout/androidaps/plugins/pump/combo/ComboPlugin.java b/combo/src/main/java/info/nightscout/androidaps/plugins/pump/combo/ComboPlugin.java
index 61dbb1d71d..a0b039ce4b 100644
--- a/combo/src/main/java/info/nightscout/androidaps/plugins/pump/combo/ComboPlugin.java
+++ b/combo/src/main/java/info/nightscout/androidaps/plugins/pump/combo/ComboPlugin.java
@@ -69,6 +69,25 @@ import info.nightscout.androidaps.utils.resources.ResourceHelper;
 import info.nightscout.androidaps.utils.sharedPreferences.SP;
 
 /**
+ * Driver for the Roche Accu-Chek Combo pump, using the ruffy app for BT communication.
+ *
+ * For boluses, the logic is to request a bolus and then read it back from the history to see what was
+ * actually delivered.
+ *
+ * TBR-handling doesn't read the pump history. On the pump, TBR records are only created after a TBR has finished.
+ * So when a TBR is started on the pump, it can't be known when it started until the TBR ends or is cancelled.
+ * Cancelling would assume a user works against the loop, and creating a temporary TBR (AAPS-side) and updating it
+ * once a record exists on the pump has other problems, since there's no ID for TBRs, only timestamps.
+ * For the regular uses where the user doesn't set TBR (or rather infrequently for some special cases), TBRs are
+ * only changed on the pump for error conditions where the pump is stopped, those need to be synced.
+ * The approach taken is to create a TBR record in AAPS when AAPS requests a TBR and forego the TBR history on
+ * the pump entirely. The pump state is refreshed often enough to tolerate not seeing the full length of a TBR
+ * on the pump if it was changed. Thus, during a pump refresh a new TBR starting now is created in AAPS if a
+ * mismatch between expected state and actual pump state is detected see {@link #checkAndResolveTbrMismatch(PumpState)}.
+ * This approach skipped implementing edge-cases that pose no real risk, in part due to limited resources to
+ * implement every edge-case scenario. Insulin amount given via boluses are significantly higher, so the
+ * priority was there to make that as safe as possible.
+ *
  * Created by mike on 05.08.2016.
  */
 @Singleton