RSS <language> tag
Usage
Specifies the language your RSS feed is written in. This makes it possible for RSS feed readers to group your website in a category based on language. Should be specified using one of the ISO language codes
Example
RSS feed with language specified:
<?xml version="1.0" encoding="ISO-8859-1" ?>
<rss version="2.0">
<channel>
<title>Landofcode.com web tutorials updates</title>
<link>http://www.landofcode.com</link>
<description>Web development tutorials</description>
<language>en-us</language>
<item>
<title>Site usability</title>
<link>http://www.landofcode.com/usability.html</link>
<description>Learn how to improve the usability of your site</description>
</item>
<item>
<title>New HTML tutorials</title>
<link>http://www.landofcode.com/html-tutorials/</link>
<description>Five new HTML tutorials have been added</description>
</item>
</channel>
</rss>