diff --git a/scripts/assemble_changelog.py b/scripts/assemble_changelog.py
index 57440bb..d11e2e8 100755
--- a/scripts/assemble_changelog.py
+++ b/scripts/assemble_changelog.py
@@ -62,6 +62,8 @@
         message = ('Lost content from {}: "{}"'.format(filename, line))
         super().__init__(message)
 
+# The category names we use in the changelog.
+# If you edit this, update ChangeLog.d/README.md.
 STANDARD_CATEGORIES = (
     b'API changes',
     b'Default behavior changes',