diff --git a/03-DESIGN/01-to-be/47-milestones/G-22-lead-answers-2.md b/03-DESIGN/01-to-be/47-milestones/G-22-lead-answers-2.md
index 0e128a54..c59be226 100644
--- a/03-DESIGN/01-to-be/47-milestones/G-22-lead-answers-2.md
+++ b/03-DESIGN/01-to-be/47-milestones/G-22-lead-answers-2.md
@@ -502,3 +502,6 @@ the principle that settles it, cited as "design 47 G A-n".
   whole: `candidates`, `manifests` and `verdicts`, for compose-candidate alone. Its watch of the indexer's `modules`
   (selfcompose shadow.go) goes; what it took from a module's record it reads from the catalog half's entry the want
   names (§421).
+- **A-309** (A-290, A-254, research 071; principles 7 and 2) A build module's `outputs` objects live as long as the
+  step key that names them: the store's age is the steps state's time to live (two days), its cap 256 MiB, and the
+  bus's own age removes an object; nothing else deletes one. The milestone's lifetime list gains this line.