diff --git a/03-DESIGN/01-to-be/47-milestones/G-20-lead-answers.md b/03-DESIGN/01-to-be/47-milestones/G-20-lead-answers.md
index 6af3b904..3de24fe0 100644
--- a/03-DESIGN/01-to-be/47-milestones/G-20-lead-answers.md
+++ b/03-DESIGN/01-to-be/47-milestones/G-20-lead-answers.md
@@ -581,3 +581,7 @@ names the principle that settles it, and is cited as "design 47 G A-n".
   state of its own on the bus, bounded by the setting `put-off-bound`: the key is the put-off record `backed-up` reads,
   its expiry raises `backup-waits` and ends the wait, so the night never holds its lock without a bound and no file
   or timer keeps it. BKP7 is not built: §555 gives `restore` its class's default with no own-item limit.
+- **A-156** (§610, A-82, design 51 *The move*; principle 7) Once distribution's `callers` list goes, the windows'
+  driver takes "every build module" as the modules that claim a build seat (`node-build-*`) in the catalog half it
+  follows, the one source A-82 gives; the holder's own per-verb `Allowed` checks go with the list, since §610's class
+  defaults are applied where the call is read, and the refusal of an unproven caller is that reader's.