たとえばShrookはRSSの302 Movedに追従するよ

# curl --dump-header h http://rss.itmedia.co.jp/rss/2.0/ep_opensource.xml

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>302 Found</title>
</head><body>
<h1>Found</h1>
<p>The document has moved <a href="http://rss.rssad.jp/rss/itm/2.0/ep_opensource.xml">here</a>.</p>
</body></html>

# cat h

HTTP/1.0 302 Moved Temporarily
Date: Fri, 02 Nov 2007 16:02:15 GMT
Server: Apache
Location: http://rss.rssad.jp/rss/itm/2.0/ep_opensource.xml
Content-Type: text/html; charset=iso-8859-1
Via: 1.1 AN-0016020114351545
X-Cache: MISS from sq02.itmedia.co.jp
Content-Length: 233
Connection: Keep-alive
Via: 1.1 AN-0016020114351545

f:id:mrmt:20200102220705p:plain