diff --git a/TODO b/TODO
index a4e003a..8d33684 100644
--- a/TODO
+++ b/TODO
@@ -3,3 +3,6 @@ If a subscription token matches an existing subscription, there's a
 collision, so choose a new token until there's no collision.
 
 Factor out commonality in subscription-management from queue/fanout/direct.
+
+SAX-style sexp reader/writer, so that we can do something sensible for
+enormous (e.g. gigabyte-sized) messages.