diff --git a/README.md b/README.md
index b8bbbf7..248f76a 100644
--- a/README.md
+++ b/README.md
@@ -25,3 +25,13 @@
 ## License
 
 Licensed under the Apache License, Version 2.0. See [LICENSE](LICENSE) for details.
+
+---
+
+## A note on the Jenkinsfile
+
+The `Jenkinsfile` in this repo is **retained for historical reference and is not operational**. The
+Jenkins server it ran on was decommissioned in August 2026.
+
+It performed a build-and-archive step that nothing downstream consumed. Publishing has always run
+through the GitHub Actions workflows in `.github/workflows`, which are unaffected.