diff --git a/matrix/synapse/README.md b/matrix/synapse/README.md
index f51741a..816908b 100644
--- a/matrix/synapse/README.md
+++ b/matrix/synapse/README.md
@@ -612,3 +612,6 @@ If you update your policy, you'll have to copy the current one to a new
 version, edit that (e.g. `0.2.html`) and change the `version` to the new
 document. Restart Synapse after that. Your users will all have to agree to the
 new policy.
+
+The options `server_notice_content` and `block_events_error` do not seem to be
+used, this is something that needs to be investigated.