diff --git a/docs/FRICTION.md b/docs/FRICTION.md
index f1d3aae..e6f2b36 100644
--- a/docs/FRICTION.md
+++ b/docs/FRICTION.md
@@ -60,3 +60,11 @@ earning its keep.
   execution?" — always answer subagent-driven here. Don't ask; default straight to
   subagent-driven (fresh subagent per task + review between tasks). → Standing
   preference; skip the execution-mode prompt.
+- `[recurring]` When a **deferred** decision later resolves, docs that referenced the
+  deferral go stale and a plan's file-map can miss them (e.g. resolving the mesh-VPN
+  choice left `new-host.md` still saying "mesh VPN (choice deferred)"; the ubongo work
+  similarly left a contradiction in CLAUDE.md). A *broadened* final grep sweep caught
+  both. → On resolving a deferred decision, grep all canonical docs for the deferral
+  language ("choice deferred", "pending", "TBD", the placeholder's name) and reconcile
+  every hit — don't rely on the plan's file-map alone. Worth a `/review-repo` check for
+  lingering "deferred/pending/TBD" references whose ADR has since resolved.