diff --git a/TODO b/TODO
index 843340d..6d7daeb 100644
--- a/TODO
+++ b/TODO
@@ -47,6 +47,7 @@ Some might be dupes, some might be done already.
 - maybe other stuff.
 - Is -Wall enabled?
 - Make mutexes recursive, so callbacks can call into the API.
+- Archivers need abstracted i/o to read from memory or files (archives in archives?)
 
 // end of TODO ...