diff --git a/.hyperhive/review-classifier.yml b/.hyperhive/review-classifier.yml
index c65d0d662..df801cadd 100644
--- a/.hyperhive/review-classifier.yml
+++ b/.hyperhive/review-classifier.yml
@@ -111,3 +111,24 @@ classifications:
       docs/5-project/ and the options reference.
     polarity: negative
     threshold: 70
+  - name: option-in-the-wrong-namespace
+    description: >-
+      A nix option the diff adds or moves under `services.hyperhive.` sits in
+      the wrong tree for what it is. `swarm.*` holds swarm-wide facts that
+      are the same on every host: the swarm's name and domain, its hives, and
+      where each service lives. `deploy.*` holds this host's own deployment
+      decisions, which differ from host to host: whether a component runs
+      here, and its ports, modes, schedules, packages and file paths, grouped
+      under the component that is deployed, as in
+      `deploy.hive-controller.egress.forward`. A setting an operator chooses
+      per host that lands under `swarm.*`, or under another module's
+      namespace such as `network.*` while it configures a component that
+      `deploy.*` already names, such as a service or the hive controller, is
+      in the wrong tree. So is a per-agent setting placed outside the agent
+      options. A read-only output or derived value (a rendered ruleset, a
+      script path), an option declared `internal = true` or `visible =
+      false`, and a rename that moves an option into the right tree are not
+      wrong. A diff that adds or moves no nix option makes the question not
+      applicable.
+    polarity: negative
+    threshold: 70
diff --git a/swarm-controller/src/review_classifier.rs b/swarm-controller/src/review_classifier.rs
index 06cb88c6b..d990e14c8 100644
--- a/swarm-controller/src/review_classifier.rs
+++ b/swarm-controller/src/review_classifier.rs
@@ -1419,6 +1419,7 @@ classifications:
                 "one-purpose",
                 "message-claims-match-diff",
                 "no-code-units-in-operator-docs",
+                "option-in-the-wrong-namespace",
             ]
         );
     }