#17714: document that the base64 codec adds a trailing newline.
diff --git a/Doc/library/codecs.rst b/Doc/library/codecs.rst
index ce850f6..460af13 100644
--- a/Doc/library/codecs.rst
+++ b/Doc/library/codecs.rst
@@ -1113,7 +1113,9 @@
| Codec | Aliases | Operand type | Purpose |
+====================+===========================+================+===========================+
| base64_codec | base64, base-64 | byte string | Convert operand to MIME |
-| | | | base64 |
+| | | | base64 (the result always |
+| | | | includes a trailing |
+| | | | ``'\n'``) |
+--------------------+---------------------------+----------------+---------------------------+
| bz2_codec | bz2 | byte string | Compress the operand |
| | | | using bz2 |