update TODO

Signed-off-by: Bjørn Mork <bjorn@mork.no>

1 files changed, 2 insertions, 0 deletions

diff --git a/TODO.md b/TODO.md
index 1ac6397..f98ab61 100644
--- a/TODO.md
+++ b/TODO.md
@@ -38,6 +38,8 @@ Items which needs to be fixed in arbitrary order:
    1. timestamp format
    2. unit/scaling
    3. QoS
+   4. retained messages - useful for units, scalers, counters
+
 * move some of the far too many command line option into the config file?