diff --git a/03-DESIGN/01-to-be/39-milestones/bus-and-switch.md b/03-DESIGN/01-to-be/39-milestones/bus-and-switch.md
index 7f549ff3..cc7d524f 100644
--- a/03-DESIGN/01-to-be/39-milestones/bus-and-switch.md
+++ b/03-DESIGN/01-to-be/39-milestones/bus-and-switch.md
@@ -524,3 +524,6 @@ written; they are cited as "design 39 bus-and-switch B*n*".
 - **B40** (§34's `target`): true for the licence §26 would move a full licence's consumers to once it reaches its
   threshold: the best licence with room now, whether or not any licence is at its threshold; so the tools say where
   consumers go next (P4).
+- **B41** (§9 and §29's whole test and the router): the manager runs whole on the test bus, and its condition is
+  taken off its subject and decoded by the operator channel's client, the contract the router reads; the router, another
+  module, is not run in this module's test, and the report says so (P1).