This document is of (Web host server) little value in an
This document is of little value in an aggregator because it contains no item elements. Surprisingly, the item element is optional in RSS 2.0 although, in practice, a typical RSS 2.0 document will have several. The following elements are optional child elements of the channel element. Some elements, which have their own child elements, are discussed further following the list. . category: This element contains information about the categories of information contained in the information feed. There can be several category elements as child elements of a channel element. . cloud: This element has several attributes that contain information specifying how a connection can be made to a cloud, allowing subscription to an information feed to be always up to date. . copyright: This contains copyright information relating to the feed. . docs: This contains a URL pointing to the RSS 2.0 specification. . generator: This contains information about the software that was used to produce the information feed. . image: This contains information so an aggregator can locate an image (in GIF, JPEG, or PNG format) to display in connection with the information feed. . language: This contains a two-letter language code, with optional extensions. Example values are en and en-us. . managingEditor: This contains the e-mail address of the contact for queries about editorial content. . pubDate: This contains the publication date for the feed. . rating: The PICS (Platform for Internet Content Selection) rating for the channel. . skipDays: This contains information indicating to an aggregator the days of the week when a feed is not expected to be updated. . skipHours: This contains information indicating to an aggregator the hours when a feed is not expected to be updated. . textinput: This displays a text box to allow the users to input information for processing on a server, typically (if the textinput element is present) on the server from which the feed originates. . ttl: This contains information about the period of time before the aggregator should check for new content. . webMaster: This contains the e-mail address of the contact for queries about technical issues relating to the information feed. Several of the previous elements are shown in the example RSS 2.0 document later in this chapter. The image Element The image element specifies an image that can be displayed along with the channel in an aggregator or other user agent. The image element has the following required child elements: 124 Chapter 12