There aren't many blogs out there that don't allow commenting of blog posts. However, RSS does not provide sufficient facilities for dealing with them. Sure RSS has the <comments> element, but it points to a HTML page that isn't machine readable. It is desirable to be able to deal with comments in the same way one deals with RSS feeds; through syndication. The RSS Well-Formed Web Module exists to fill this gap.
An example using the most popular element of the Well-Formed Web RSS Module is shown below:
<?xml version="1.0">
<rss version="2.0"
xmlns:wfw="http://wellformedweb.org/CommentAPI/"
>
<channel>
<title>Example</title>
<description>An RSS Example with WFW</description>
<lastBuildDate>Sun, 15 May 2005 13:02:08 -0500</lastBuildDate>
<link>http://www.example.com</link>
<item>
<title>I like Root Beer</title>
<guid>d77d2e80-0487-4e8c-a35d-a93f12a0ff7d:article:54321</guid>
<pubDate>Sun, 15 May 2005 13:02:08 -0500</pubDate>
<link>http://www.example.com/article/54321</link>
<wfw:commentRss>http://www.example.com/feed/rss/54321/comments</wfw:commentRss>
</item>
<item>
<title>Rain is Wet</title>
<guid>d77d2e80-0487-4e8c-a35d-a93f12a0ff7d:article:54320</guid>
<pubDate>Sun, 15 May 2005 10:55:12 -0500</pubDate>
<link>http://www.example.com/article/54320</link>
<wfw:commentRss>http://www.example.com/feed/rss/54320/comments</wfw:commentRss>
</item>
<item>
<title>Huh?!</title>
<guid>d77d2e80-0487-4e8c-a35d-a93f12a0ff7d:article:54319</guid>
<pubDate>Sun, 15 May 2005 08:14:11 -0500</pubDate>
<link>http://www.example.com/article/54319</link>
<wfw:commentRss>http://www.example.com/feed/rss/54319/comments</wfw:commentRss>
</item>
</channel>
</rss>
The <wfw:commentRss> element is the reason that the Well-Formed Web RSS Module is popular. This element lets you syndicate your comments. The URI in the <wfw:commentRss> element must point to an RSS feed containing the comments for the <item> it is contained in.