Category is category metadata for Feeds and Entries.

Cloud allows processes to register with a cloud to be notified of updates to the channel, implementing a lightweight publish-subscribe protocol for RSS feeds.

Enclosure is a media object that is attached to the item.

Feed is an RSS Feed.

GUID is a unique identifier for an item.

Image is an image that represents the feed.

Item is an RSS Item.

Parser is a RSS Parser.

Source contains feed information for another feed if a given item came from that feed.

TextInput specifies a text input box that can be displayed with the channel.