diff --git a/wizard-work/beam/sha256_manifest.py b/wizard-work/beam/sha256_manifest.py
index 9202b98..c75212d 100644
--- a/wizard-work/beam/sha256_manifest.py
+++ b/wizard-work/beam/sha256_manifest.py
@@ -1,5 +1,11 @@
 #!/usr/bin/env python3
-"""Generate and verify a SHA-256 manifest for a directory of files."""
+"""Generate and verify a SHA-256 manifest for a directory of files.
+
+Retained for the sha256sum-compatible `digest  path` line format only. The
+canonical directory manifest for this lane is `manifest.py`: it records sizes,
+symlink targets and directory symlinks, and carries the 0/1/2 exit contract.
+Use this file when a consumer needs the plain text shape; use that file otherwise.
+"""
 import argparse
 import hashlib
 import os