Oh rats, sorry, I always forget to mention versions:
EE 1.6.3 (haven’t upgraded yet as I stupidly hacked part of the core and need to do a work around.)
DF 2.1.0.
I am using the default forum rss and atom template:
{?xml version="1.0" encoding="{encoding}" ?}
<feed >
<title type="text">{exp:xml_encode}{forum_name}{/exp:xml_encode}</title>
<link rel="alternate" type="text/html" href="{forum_url}" />
<link rel="self" type="application/atom+xml" href="{forum_rss_url}" />
<updated>{gmt_edit_date format='%Y-%m-%dT%H:%i:%sZ'}</updated>
<rights>Copyright (c) {gmt_date format="%Y"}</rights>
<generator uri="http://expressionengine.com/" version="{version}">ExpressionEngine</generator>
<id>tag:{trimmed_url},{gmt_date format="%Y:%m:%d"}</id>
{rows}
<entry>
<title>{exp:xml_encode}{title}{/exp:xml_encode}</title>
<link rel="alternate" type="text/html" href="{path:view_thread}" />
<id>tag:{trimmed_url},{gmt_post_date format="%Y"}:{relative_url}/viewthread/.{topic_id}</id>
<published>{gmt_post_date format="%Y-%m-%dT%H:%i:%sZ"}</published>
<updated>{gmt_edit_date format='%Y-%m-%dT%H:%i:%sZ'}</updated>
<author><name>{author}</name></author>
<content type="html">
<![CDATA[
{body}
]]>
</content>
</entry>
{/rows}
</feed>
and
{?xml version="1.0" encoding="{encoding}" ?}
<rss version="2.0"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
xmlns:admin="http://webns.net/mvcb/"
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:content="http://purl.org/rss/1.0/modules/content/">
<channel>
<title>{exp:xml_encode}{forum_name}{/exp:xml_encode}</title>
<link>{forum_url}</link>
<description>{exp:xml_encode}{forum_name}{/exp:xml_encode}</description>
<dc:language>{forum_language}</dc:language>
<dc:rights>Copyright {gmt_date format="%Y"}</dc:rights>
<dc:date>{gmt_date format="%Y-%m-%dT%H:%i:%s%Q"}</dc:date>
<admin:generatorAgent rdf:resource="http://expressionengine.com/" />
{rows}
<item>
<title>{exp:xml_encode}{title}{/exp:xml_encode}</title>
<link>{exp:xml_encode}{path:view_thread}{/exp:xml_encode}</link>
<guid>{path:view_thread}#When:{gmt_post_date format="%H:%i:%sZ"}</guid>
<description>{exp:xml_encode}{body}{/exp:xml_encode}</description>
<dc:date>{gmt_post_date format="%Y-%m-%dT%H:%i:%s%Q"}</dc:date>
</item>
{/rows}
</channel>
</rss>
