diff --git a/app/Services/Pacs/Sync/Pipes/FilterStudies.php b/app/Services/Pacs/Sync/Pipes/FilterStudies.php
index 8fb1aa6..3af5402 100644
--- a/app/Services/Pacs/Sync/Pipes/FilterStudies.php
+++ b/app/Services/Pacs/Sync/Pipes/FilterStudies.php
@@ -42,6 +42,7 @@ private function checkUpdate(string $orthanc_uuid, StudiesSync $sync, Collection
         }
 
         if ($study_status < StudyLevelStatus::Unassigned->value) {
+            // this is an "unstable" study. queue for update
             $sync->getUpdateQueue()->add($orthanc_uuid);
         }
     }