http://confluence.atlassian.com/display/DOC/Using+the+RSS+Feed+Builder

The doc is a bit unclear in general and could do with a cleanup. Specifically it needs to clarify:

• A feed can either be anonymous or authenticated
• If your server does not allow anonymous access, only authenticated feeds are offered
• If your server allows anonymous access, the "feed permission" section will appear
• If a feed is anonymous, you only get anonymously-viewable content in the feed regardless of whether you're a user or not

Ref: http://twitter.com/ZAThomas/statuses/789161053