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 3a3cc29f..37b257eb 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
@@ -150,3 +150,7 @@ the principle that settles it, cited as "design 47 G A-n".
 - **A-216** (amends A-181; principles 2 and 7) The builder's `build.ended` stream, kept last per subject, has no age
   bound, only a cap in bytes: one end per fingerprint is the record of what was built, so a module unchanged for any
   time is still known built after a restart.
+- **A-217** (§298, §300, A-167, A-132; principles 2 and 7) A want reverts when its fingerprint is one the module had
+  in an earlier assignment graph revision than the one it now runs from, by the revisions' own numbers; the running
+  manifest is the catalog entry of the fingerprint the node-engine seat's `running` names, read through the catalog
+  seat's `entry`, and `FormChanges` compares it with the want's entry.