I get validation errors on the code here, but it still works. I think the problem is that the validator is looking at the code before MODX processes the tags, especially the <link> tag.
Hi. I don’t know. I can’t set it up. RSS cannot be imported to the social network. The support of the social network said that the RSS 1 standard is needed, not Atom
I don’t think you need much for a simple feed. Here’s an example I found for RSS 2.0:
<rss version="2.0">
<channel>
<title>My Example Updates</title>
<link>http://example.com/</link>
<description>Things that I've recently updated.</description>
<item>
<title>New Paper Published</title>
<link>http://example.com/2002/09/01</link>
<description>My paper was published in the Example Journal today.</description>
</item>
<item>
<title>Research Project Results</title>
<link>http://example.com/2002/09/02</link>
</item>
</channel>
</rss>