Issue #26736: Used HTTPS for external links in the documentation if possible.
diff --git a/Doc/library/htmllib.rst b/Doc/library/htmllib.rst
index e5045dd..08ac577 100644
--- a/Doc/library/htmllib.rst
+++ b/Doc/library/htmllib.rst
@@ -64,7 +64,7 @@
 .. class:: HTMLParser(formatter)
 
    This is the basic HTML parser class.  It supports all entity names required by
-   the XHTML 1.0 Recommendation (http://www.w3.org/TR/xhtml1).   It also defines
+   the XHTML 1.0 Recommendation (https://www.w3.org/TR/xhtml1).   It also defines
    handlers for all HTML 2.0 and many HTML 3.0 and 3.2 elements.