diff --git a/TransportApp.markdown b/TransportApp.markdown
index e200b9b..c9cea15 100644
--- a/TransportApp.markdown
+++ b/TransportApp.markdown
@@ -15,6 +15,7 @@ TransportApp uses a single channel with a random identifer:
 
 ### Storage policy
 
+* Invalid messages are not stored.
 * For each transport, the local message with the highest version is stored, and any other versions are deleted.
 * For each transport and each remote device, the remote message with the highest version is stored, and any other versions are deleted.