The RSS Auto-discovery link tag has been changed.
This change comes in response to (valid) criticism that the old way was too general, and could cause confusion if, in the future, there were other XML-based formats that pages wanted to link to. Using a more specific MIME type (the exact type was suggested by Dan Brickley) solves this potential problem, and the more specific title goes along with it.
Here is the link tag as it now stands:
<link rel=”alternate” type=”application/rss+xml” title=”RSS” href=”url/to/rss/file” />