diff --git a/aider/main.py b/aider/main.py
index a604c5f64..0bd3668ad 100644
--- a/aider/main.py
+++ b/aider/main.py
@@ -541,6 +541,7 @@ def main(argv=None, input=None, output=None, force_git_root=None, return_coder=F
     all_files = args.files + (args.file or [])
     fnames = [str(Path(fn).resolve()) for fn in all_files]
     read_only_fnames = [str(Path(fn).resolve()) for fn in (args.read or [])]
+    #ai expand any of the read_only_fnames which are dirs to be all the files under them!
     if len(all_files) > 1:
         good = True
         for fname in all_files: