Because RSS feeds typically use HTTP, and are categorized based on the domain from which they are served, writing policy to handle them (for purposes of authentication exemptions, caching decisions, permission or bandwidth management) is not obvious. However, RSS feeds identify themselves in the HTTP response header as traffic is returned to the user and we can use this to write policy on the ProxySG.
In content policy language, a destination to match against RSS content appears as follows:
response.header.Content-Type="application/rss+xml"
Here's how to create the same object in the visual policy manager: