diff --git a/.pre-commit-hooks.yaml b/.pre-commit-hooks.yaml
index 36c9884..20026f5 100644
--- a/.pre-commit-hooks.yaml
+++ b/.pre-commit-hooks.yaml
@@ -197,6 +197,9 @@
 
     Background: In a big codebase, the exclude lists can be quite long and it's easy to make a typo or forget to remove an entry when it's no longer needed.
     This hook helps you to maintain a clean and up to date exclude list.
+
+    Note: This hook deliberately only supports simple `|`-separated lists of file paths in `exclude` fields — complex regular expressions are not supported.
+    Keeping exclusions as plain `|`-separated paths also makes it easier for humans to maintain an overview of what is excluded.
   entry: check-useless-exclude-paths-hooks
   pass_filenames: false
   always_run: true
diff --git a/README.md b/README.md
index 9bc467b..1461123 100644
--- a/README.md
+++ b/README.md
@@ -167,6 +167,9 @@ Check for non existing and duplicate paths in `.pre-commit-config.yaml`.
 Background: In a big codebase, the exclude lists can be quite long and it's easy to make a typo or forget to remove an entry when it's no longer needed.
 This hook helps you to maintain a clean and up to date exclude list.
 
+Note: This hook deliberately only supports simple `|`-separated lists of file paths in `exclude` fields — complex regular expressions are not supported.
+Keeping exclusions as plain `|`-separated paths also makes it easier for humans to maintain an overview of what is excluded.
+
 ### `print-pre-commit-metrics`
 
 Count the number of excludes in `.pre-commit-config.yaml` and print them in json format.