Issue 12139: add CCC command support to FTP_TLS class to revert the SSL connection back to clear-text.
diff --git a/Doc/library/ftplib.rst b/Doc/library/ftplib.rst
index f4205f4..087e200 100644
--- a/Doc/library/ftplib.rst
+++ b/Doc/library/ftplib.rst
@@ -426,6 +426,14 @@
Set up secure control connection by using TLS or SSL, depending on what specified in :meth:`ssl_version` attribute.
+.. method:: FTP_TLS.ccc()
+
+ Revert control channel back to plaintex. This can be useful to take
+ advantage of firewalls that know how to handle NAT with non-secure FTP
+ without opening fixed ports.
+
+ .. versionadded:: 3.3
+
.. method:: FTP_TLS.prot_p()
Set up secure data connection.