Berker Peksag added the comment:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
I think that HTML output suggests that their server configuration is broken. If you look at further down the page there is this error message:
<p>Something has triggered missing webpage on your website. This is the default 404 error page for <strong>nginx</strong> that is distributed with EPEL. It is located <tt>/usr/share/nginx/html/404.html</tt></p>
$ curl -I https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT HTTP/1.1 404 Not Found ...
https://support.pkware.com/display/PKZIP/Application+Note+Archives might be a suitable alternative to the broken link. I'm adding Serhiy to nosy list since he knows a lot about the ZIP file format.
---------- assignee: -> docs@python components: +Documentation nosy: +berker.peksag, docs@python, serhiy.storchaka resolution: not a bug -> stage: resolved -> needs patch status: closed -> open type: -> behavior versions: +Python 3.5, Python 3.7