diff --git a/TODO b/TODO
index 0dd20d3..591706c 100644
--- a/TODO
+++ b/TODO
@@ -4,6 +4,11 @@
    ° Valgrind / libconfuse bugs (Listener & Aggregator):
    .   http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=639074
    .   http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=639115
+- Handle the aggregation format version
+   In the aggregation files, a version number describing the file format
+   should be added (as the 2nd field, right after the client's MAC
+   address). That would allow the positioning server to handle several
+   formats instead of just the last version.
 - Check the size of the received packets to avoid buffer overflows.
 - Use select(2) or poll(2)
    Using polling for sockets would avoid setting up some threads,