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 82f04149..7562b147 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
@@ -675,3 +675,8 @@ names the principle that settles it, and is cited as "design 47 G A-n".
   `view_read_answers` (mesh-sdk `views.ReadTool`, in the view's tools bundle, the teller among its callers) and a
   marks state `view-marks` (history 1), as the assigner and the indexer have; the teller's side is the same, with
   `teller_read_answers` and `teller-marks`.
+- **A-179** (refines A-165; §610, §336; principles 3 and 7) Where a seat's verb is answered, an unproven caller is
+  refused, and so is every caller when the verb's effective callers are empty; a proven caller is taken as among
+  them, since the grants part composes a verb's call subject only for the callers its effective list names, so the
+  bus holds the rest out. `seatdef.DefaultCallers` follows §610 (act, warrant and accept: operator, sessions and
+  invokers).