diff --git a/communication.md b/communication.md
index c11d4040b738320b9d1ec50dd079f359faec7ec0..30c958c3ea3ed92e18ee8af6a25a055105fa2602 100644
--- a/communication.md
+++ b/communication.md
@@ -9,7 +9,9 @@ Lossy communication. Protocols to detect and handle.
 Some service calls return a list of com-uuid which can be checked for
 if the message they correspons to arrived properly.
 
-QUERY: Is it one per message or one per message-unit?
+there is one uuid per "data". So one node distributed to 5 agents will
+give on com-uuid.  There is a service call to check that this com-uuid
+have received confirmation from all 5 agents then.
 
 ## DistributeTree