diff --git a/frontend/src/api/campaigns.ts b/frontend/src/api/campaigns.ts
index e7795c2..35e1c8d 100644
--- a/frontend/src/api/campaigns.ts
+++ b/frontend/src/api/campaigns.ts
@@ -91,6 +91,8 @@ export interface CampaignModificationRequest {
   campaign_name: string | null;
   requested_by: string | null;
   action: ModificationRequestAction;
+  /** Null once the underlying Test is deleted (e.g. an approved "remove_test"
+   * request) — this row is the surviving audit record, not a live link. */
   test_id: string | null;
   test_name: string | null;
   order_index: number | null;