nsIFeed Interface

 No one really knows what cloud is for.

 It supposedly enables some sort of interaction with an XML-RPC or
 SOAP service.

attribute nsIWritablePropertyBag2 cloud

 The total number of enclosures found in the feed.

attribute long enclosureCount

 Information about the software that produced the feed.

attribute nsIFeedGenerator generator

 An image url and some metadata (as defined by RSS2).

attribute nsIWritablePropertyBag2 image

 The items or entries in feed.

attribute nsIArray items

 Days to skip fetching. This field was supposed to designate
 intervals for feed fetching. It's not generally implemented. For
 example, if this array contained "Monday", aggregators should not
 fetch the feed on Mondays.

attribute nsIArray skipDays

 Hours to skip fetching. This field was supposed to designate
 intervals for feed fetching. It's not generally implemented. See
 <http://blogs.law.harvard.edu/tech/rss> for more information.

attribute nsIArray skipHours

 
 Uses description, subtitle, and extensions
 to generate a summary. 

attribute nsIFeedTextConstruct subtitle

 No one really knows what textInput is for.

 See
 <http://www.cadenhead.org/workbench/news/2894/rss-joy-textinput>
 for more details.

attribute nsIWritablePropertyBag2 textInput

 The type of feed. For example, a podcast would be TYPE_AUDIO.

readonly attribute unsigned long type