Clarify that IMAP4() implicitly calls open(), and that logout() implicitly calls shutdown().
diff --git a/Doc/library/imaplib.rst b/Doc/library/imaplib.rst
index 78adcf8..1d92fe5 100644
--- a/Doc/library/imaplib.rst
+++ b/Doc/library/imaplib.rst
@@ -298,9 +298,10 @@
.. method:: IMAP4.open(host, port)
- Opens socket to *port* at *host*. The connection objects established by this
+ Opens socket to *port* at *host*. This method is implicitly called by
+ the :class:`IMAP4` constructor. The connection objects established by this
method will be used in the ``read``, ``readline``, ``send``, and ``shutdown``
- methods. You may override this method.
+ methods. You may override this method.
.. method:: IMAP4.partial(message_num, message_part, start, length)
@@ -390,7 +391,8 @@
.. method:: IMAP4.shutdown()
- Close connection established in ``open``. You may override this method.
+ Close connection established in ``open``. This method is implicitly
+ called by :meth:`IMAP4.logout`. You may override this method.
.. method:: IMAP4.socket()