#21169: add comment and doc update for getpass change.
diff --git a/Lib/getpass.py b/Lib/getpass.py
index 2740363..7c4e976 100644
--- a/Lib/getpass.py
+++ b/Lib/getpass.py
@@ -138,6 +138,7 @@
         try:
             stream.write(prompt)
         except UnicodeEncodeError:
+            # Use replace error handler to get as much as possible printed.
             prompt = prompt.encode(stream.encoding, 'replace')
             prompt = prompt.decode(stream.encoding)
             stream.write(prompt)