diff --git a/tix/tix-upgrade b/tix/tix-upgrade
index 0188f83b..5f327715 100755
--- a/tix/tix-upgrade
+++ b/tix/tix-upgrade
@@ -186,6 +186,7 @@ fi
 # Fetch each binary package from the mirror.
 # TODO: Handle new mandatory / recommended ports.
 # TODO: Handle renamed ports.
+# TODO: Tracking sets like minimal/basic/full.
 mkdir -p -- "$cachedir/repository"
 packages=""
 for package in $(LC_ALL=C ls -- "$collection/tix/tixinfo"); do