Issue #26736: Used HTTPS for external links in the documentation if possible.
diff --git a/Doc/howto/functional.rst b/Doc/howto/functional.rst
index 9d2991f..62792b8 100644
--- a/Doc/howto/functional.rst
+++ b/Doc/howto/functional.rst
@@ -1171,9 +1171,9 @@
 Mertz also wrote a 3-part series of articles on functional programming
 for IBM's DeveloperWorks site; see
 
-`part 1 <http://www.ibm.com/developerworks/linux/library/l-prog/index.html>`__,
-`part 2 <http://www.ibm.com/developerworks/linux/library/l-prog2/index.html>`__, and
-`part 3 <http://www.ibm.com/developerworks/linux/library/l-prog3/index.html>`__,
+`part 1 <https://www.ibm.com/developerworks/linux/library/l-prog/index.html>`__,
+`part 2 <https://www.ibm.com/developerworks/linux/library/l-prog2/index.html>`__, and
+`part 3 <https://www.ibm.com/developerworks/linux/library/l-prog3/index.html>`__,
 
 
 Python documentation
diff --git a/Doc/howto/logging-cookbook.rst b/Doc/howto/logging-cookbook.rst
index c371267..3ee65c4 100644
--- a/Doc/howto/logging-cookbook.rst
+++ b/Doc/howto/logging-cookbook.rst
@@ -767,11 +767,11 @@
 Inserting a BOM into messages sent to a SysLogHandler
 -----------------------------------------------------
 
-`RFC 5424 <http://tools.ietf.org/html/rfc5424>`_ requires that a
+`RFC 5424 <https://tools.ietf.org/html/rfc5424>`_ requires that a
 Unicode message be sent to a syslog daemon as a set of bytes which have the
 following structure: an optional pure-ASCII component, followed by a UTF-8 Byte
 Order Mark (BOM), followed by Unicode encoded using UTF-8. (See the `relevant
-section of the specification <http://tools.ietf.org/html/rfc5424#section-6>`_.)
+section of the specification <https://tools.ietf.org/html/rfc5424#section-6>`_.)
 
 In Python 2.6 and 2.7, code was added to
 :class:`~logging.handlers.SysLogHandler` to insert a BOM into the message, but
diff --git a/Doc/howto/pyporting.rst b/Doc/howto/pyporting.rst
index 0b4fa83..29ba8e5 100644
--- a/Doc/howto/pyporting.rst
+++ b/Doc/howto/pyporting.rst
@@ -379,10 +379,10 @@
 .. _cheat sheet: http://python-future.org/compatible_idioms.html
 .. _coverage.py: https://pypi.python.org/pypi/coverage
 .. _Futurize: http://python-future.org/automatic_conversion.html
-.. _Modernize: http://python-modernize.readthedocs.org/en/latest/
+.. _Modernize: https://python-modernize.readthedocs.org/en/latest/
 .. _Porting to Python 3: http://python3porting.com/
 .. _Pylint: https://pypi.python.org/pypi/pylint
-.. _Python 3 Q & A: http://ncoghlan-devs-python-notes.readthedocs.org/en/latest/python3/questions_and_answers.html
+.. _Python 3 Q & A: https://ncoghlan-devs-python-notes.readthedocs.org/en/latest/python3/questions_and_answers.html
 
 .. _python-future: http://python-future.org/
 .. _python-porting: https://mail.python.org/mailman/listinfo/python-porting
diff --git a/Doc/howto/unicode.rst b/Doc/howto/unicode.rst
index 8138a09..afd89c7 100644
--- a/Doc/howto/unicode.rst
+++ b/Doc/howto/unicode.rst
@@ -211,7 +211,7 @@
 
 To help understand the standard, Jukka Korpela has written an introductory guide
 to reading the Unicode character tables, available at
-<http://www.cs.tut.fi/~jkorpela/unicode/guide.html>.
+<https://www.cs.tut.fi/~jkorpela/unicode/guide.html>.
 
 Another good introductory article was written by Joel Spolsky
 <http://www.joelonsoftware.com/articles/Unicode.html>.
diff --git a/Doc/howto/urllib2.rst b/Doc/howto/urllib2.rst
index 3cac993..3550112 100644
--- a/Doc/howto/urllib2.rst
+++ b/Doc/howto/urllib2.rst
@@ -112,7 +112,7 @@
 
 Note that other encodings are sometimes required (e.g. for file upload from HTML
 forms - see `HTML Specification, Form Submission
-<http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13>`_ for more
+<https://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13>`_ for more
 details).
 
 If you do not pass the ``data`` argument, urllib2 uses a **GET** request. One
@@ -388,7 +388,7 @@
 ``httplib.HTTPMessage`` instance.
 
 Typical headers include 'Content-length', 'Content-type', and so on. See the
-`Quick Reference to HTTP Headers <http://www.cs.tut.fi/~jkorpela/http.html>`_
+`Quick Reference to HTTP Headers <https://www.cs.tut.fi/~jkorpela/http.html>`_
 for a useful listing of HTTP headers with brief explanations of their meaning
 and use.
 
@@ -573,5 +573,5 @@
        scripts with a localhost server, I have to prevent urllib2 from using
        the proxy.
 .. [#] urllib2 opener for SSL proxy (CONNECT method): `ASPN Cookbook Recipe
-       <http://code.activestate.com/recipes/456195/>`_.
+       <https://code.activestate.com/recipes/456195/>`_.