diff --git a/.github/CONTROL-PR.md b/.github/CONTROL-PR.md
new file mode 100644
index 00000000..574b320a
--- /dev/null
+++ b/.github/CONTROL-PR.md
@@ -0,0 +1,16 @@
+# Control PR (DO NOT MERGE)
+
+This branch exists only to answer one question: does the hf-adapters test
+suite pass on the **legacy** CI runner image, with no source changes?
+
+- Base: `main`, unchanged. This file is the only diff, so the branch stays a
+  faithful baseline. It forces a real `regression` run (an empty commit can
+  resolve oddly).
+- Runners: the default `image_torch_spyre` (legacy `2.0/ci` image). No image
+  redirect, no venv changes, no test edits.
+- Pairs with the `/next`-image shadow PR (same suite, `/next` runner image).
+  Compare the two: if the shadow run is red while this control is green, the
+  `/next` image is the cause, not the tests.
+- Fixes belong in dedicated fix PRs, never here.
+
+Delete this file before ever considering a merge; this branch is a throwaway.