I needed to check my notes on RSS autodiscovery; I wrote about it in passing in my article on Venus, and on returning found this article by Pete Freitag. The key idiom is to add a <link> tag in the <head> section of your html page. Here are more notes …
An example,
<link rel="alternate" type="application/rss+xml" title="${RSS feed title}" href="${URL}" />
If the feed is an atom feed then the type should be “application/atom+xml” & RDF is “application/rdf+xml.”.