RSS 2.0 Standard 2

rss| Standard Optional channel elements

The following is a list of optional channel (channel) elements.

01. language
Name: Language
Description: The language used by the channel. For example, on a Web site, all Italian sites are allowed to be aggregated to the appropriate groupings. For this element, the values that can be used refer to the list provided by Netscape. Or you can refer to the list of the definition of the consortium.
Example: en-us.

02. Copyright
Name: Copyright
Description: The copyright notice for the content of the channel.
Example: Copyright 2002, Spartanburg Herald-journal

03. Managingeditor
Name: Managingeditor
Description: The email address of the editor of the channel content.
Example: geo@herald.com (George Matesky)

04. Webmaster
Name: Webmaster
Description: The email address of the channel technical support person.
Example: Betty@herald.com (Betty Guernsey)

05. pubdate
Name: pubdate
Description: Date on which the channel content was released. All dates and times must follow the RFC 822 specification, but the year can be represented by 2 or 4 letters (4 letters preferred).
Example: Sat, Modified SEP 2002 00:00:01 GMT

06. Lastbuilddate
Name: Lastbuilddate
Description: The last modification time of the channel content.
Example: Sat, Modified SEP 2002 09:42:31 GMT

07. Category
Name: Category
Description: Specifies one or more categories to which the channel belongs. Follow the same rules as the item-level category element. See here for details.
Example:<category>newspapers</category>

08. Generator
Name: Generator
Description: A string indicating the name of the program that generated the channel.
Example: Mightyinhouse Content System v2.3

09. Docs
Name: Docs
Description: The URL link address to the format description document used for the RSS file.
Example: Http://blogs.law.harvard.edu/tech/rss.

10. Cloud
Name: Cloud
Description: Allows you to register a cloud to handle update notifications for the channel and implement a lightweight subscription agreement for RSS feeds, as described here .
Example: <cloud domain= "rpc.sys.com" port= "path=" "/RPC2" registerprocedure= "Pingme" protocol= "soap"/>

11. TTL
Name: TTL
Description: The TTL is the abbreviation for time to live, indicating the lifetime. It represents the time that the channel can cache before it is updated from the source. See here for details.
Example:<ttl>60</ttl>.

12. Image
Name: Image
Description: Specifies a GIF, JPEG, or PNG image that can be displayed on the channel. See here for details.
Example:.

13. Rating
Name: Rating
Description: PICS content rating information for the channel.
Example:.

14. TextInput
Name: TextInput
Description: Specifies a text entry box that can be displayed on the channel. See here for details.
Example:.

15. Skiphours
Name: skiphours
Description: Prompts the aggregator to skip the time periods for those hours. See here for details.
Example:.

16. Skipdays
Name: Skipdays
Description: Prompts the aggregator to skip the time periods for those days. See here for details.
Example:.

<channel> child elements <image>

<image> is an optional child element of <channel> that itself contains three required and three optional child elements.

<url> is a URL-linked address for a GIF, JPEG, or PNG image file that represents the entire channel.

<title> describes the image above, used for the ALT attribute of in the HTML language when the channel is displayed in HTML.

<link> is the URL of the site to connect to, and the connection to the image points to the site when the channel is displayed. (In practice,<title> and <link> should have the same value as the <title> and <link> of the channel).

Optional elements include <width> and <description> is the text in the title attribute of link, which will be displayed when the page is invoked.

The maximum image width is 144, and the default value is 88.

The maximum image height is 400, and the default value is 31.

<channel> child elements <cloud>

<cloud> is an optional child element of <channel>.

It specifies a Web service that can support the Rsscloud interface, and Rsscloud interfaces can be implemented in Http-post, XML-RPC, or SOAP1.1.

The goal is to allow a lightweight subscription protocol for RSS feeds by registering a cloud to handle update notifications for the channel.

<cloud domain= "rpc.sys.com" port= "path="/RPC2 "registerprocedure=" mycloud.rsspleasenotify "protocol=" XML-RPC "/>

In this example, to request a channel notification, you need to send an XML-RPC message to the Rpc.sys.com 80 port, the path is/RPC2. The program being invoked is mycloud.rsspleasenotify.

See here for a detailed description of this element and a description of the Rsscloud interface.

<channel> child elements <ttl>

An optional child element of <ttl><channel>.

The TTL is the abbreviation for time to live, indicating the lifetime. It represents the time that the channel can be cached before it is refreshed from the source. This allows RSS feeds to be managed by a network that supports file sharing, such as Gnutella.

Example: <ttl>60</ttl>

<channel> child elements <textInput>

The channel can optionally contain a <textInput> child element, which itself contains four required child elements.

<title>--the label of the submit button for the text input area.

<description>--the description of the text input area.

<name>--the name of the text object in the text entry area.

<link>--the URL link address of the CGI script that handles text input requests.

The purpose of using <textInput> elements seems to be somewhat mysterious. You can use it to provide a search engine input box, or let readers provide feedback. Many aggregators ignore this element.

Elements of <item>

A channel can contain many <item> elements. A project can represent a "story"-say, a newspaper or magazine story; If so, the project description is a summary of the story, and the project link points to the link location of the entire story. A project can also be complete in itself, and if so, the description of the project contains the text (as a whole can be encoded in HTML format; see examples ), and links and headings can be omitted. All elements of the project are optional, but include at least one title (title) or description (description).

01. Title
Name: Title
Description: Title of item.
Example: Venice Film Festival tries to Quit sinking

02. Link
Name: Link
Description: Item's URL link address.
Example:http://nytimes.com/2004/12/07FEST.html

03. description
Name: Description
Description: The item's summary.
Example: Some of the most heated chatter at the Venice Film Festival this week is about the way that the arrival of the stars a t the Palazzo del Cinema was being staged.

04. author
Name: Author
Description: The email address of item author. See here for details.
Example:.

05. Category
Name: Category
Description: Contains item in one or more categories. See here for details.
Example:.

06. comments
Name: Comments
Description: The URL link address of the comment associated with item. See here for details.
Example:.

07. Enclosure
Name: Enclosure
Description: Item attached to the media object. See here for details.
Example:.

08. GUID
Name: GUID
Description: A string that can uniquely determine the identity of the item. See here for details.
Example:.

09. pubdate
Name: pubdate
Description: Time of item release. See here for details.
Example:.

10. Source
Name: source
Description: RSS channel source. See here for details.
Example:.

<item> child elements <source>

<source> is an optional child element of <item>.

Its value is the name of the RSS channel that item belongs to, derived from title. It has a property URL that must be included, which is linked to the XML serialization source.

<source url= "Http://www.tomalak.org/links2.xml" >tomalak ' s realm</source>

The role of this element is to enhance the reputation of the link, thereby further promoting the source of the news project. It can be used in the post command of the aggregator. ,<source> should be automatically generated when an item is submitted from an aggregator through a webblog editing tool.

<item> child elements <enclosure>

<enclosure> is an optional child element of <item>.

It has three required properties. The URL property indicates the location of the enclosure, the length property indicates its byte size, and the Type property indicates its standard MIME type.

The URL here must be an HTTP URL.

<enclosure url= "Http://www.scripting.com/mp3s/weatherReportSuite.mp3" length= "12216320" type= "Audio/mpeg"/>

See here for its use-case description.

<item> child elements <category>

<category> is an optional child element of <item>.

It has an optional attribute, domain, which is a string used to define the taxonomy.

The value of the node is a slash-separated string that is used to indicate the hierarchical position in the specified classification method. The processor can establish a contract for classification recognition. Here are two examples:

<category>grateful dead</category>

<category domain= "Http://www.fool.com/cusips" >MSFT</category>

You can include many <category> elements for different fields as needed, and you can have a cross-reference item in different parts of the same domain.

<item> child elements <pubDate>

<pubDate> is an optional child element of <item>.

Its value is a date indicating when the project was published. If it is a future date, the aggregator can choose not to display the item until the date arrives.

<pubdate>sun, May 2002 15:21:36 gmt</pubdate>

<item> child elements <guid>

<guid> is an optional child element of <item>.

GUIDs are abbreviations for globally unique identifier. It is a string that uniquely identifies this <item>. After publication, the aggregator can choose to use the string to determine whether this <item> is new.

<guid>http://some.server.com/weblogItem3207</guid>

The GUID does not have a specific syntax rule. The aggregator must treat them as a string. Generating a unique string GUID depends on the source of the seed.

If the GUID element has a Ispermalink attribute and the value is true, the interpreter considers it to be the permalink of the item. Permalink is a URL link that can be opened in a Web browser, pointing to the full item described by the <item> node. For example:

<guid ispermalink= "true" >http://inessential.com/2002/09/01.php#a2</guid>

Ispermalink is an optional attribute, and the default value is true. If the value is False, the GUID will not be considered a URL or a URL to any object.

<item> child elements <comments>

<comments> is an optional child element of <item>.

If it appears, it points to the URL of the comment associated with the item.

<comments>http://ekzemplo.com/entry/4403/comments</comments>

For more information, please see here .

<item> child elements <author>

<author> is an optional child element of <item>.

It is the item author's e-mail address L. For newspapers and magazines propagated through RSS, the author may be the person who wrote the article as described in the item. For clustered webblogs, the author may not be an editor or a webmaster. For the webblog of personal maintenance, it is meaningful to ignore <author> nodes.

<author>lawyer@boyer.net (lawyer Boyer) </author>

Comments

The RSS limit <link> and <url> element's data first letter is not a space character. The data for these elements must begin in the format specified in the iana-registered URI scheme, such as http://, https://, news://, mailto: and ftp://. Before the RSS2.0 specification, the RSS specification allows only http://and ftp://, whereas in practice other URI schemes are widely used by content developers and supported by aggregators. Aggregators may have some limitations on the URI schemes they support, and content developers should not assume that all aggregators support all URI schemes.

In the RSS 0.91 specification, the various elements are limited to 500 or 100 characters. There are no more than 15 <item> elements in a channel that conforms to the 0.91 specification. In RSS 0.92 and later specifications, these character lengths or XML-level restrictions are no longer available. The processor may impose some of its own limitations, and the creator may have some of its own parameters to choose from, which can dictate that no more than a certain number of <item> elements in a channel, or that the strings are limited to a certain length.

As mentioned above, in the RSS 2.0 specification, a channel-level classification feature is used for a directory system when linking a channel to its identity. For example, if you link a channel to its SYNDIC8 identity, it will include a taxonomy element as a child of the channel, it has the domain "Syndic8" attribute, and the identity is identified for your channel in the SYNDIC8 database. The correct category element script should be the <category domain= "Syndic8" >1765</category>.

A frequently asked question is about how <guid> differs from <link>. Do they refer to the same thing? In some content systems, but may not be in other content systems. In some systems,<link> is a permanent link to a blog entry. Then in other systems, each <item> is a summary of a long article,<link> points to this article, and <guid> is a permanent link to this blog entry. In all cases, it is recommended to provide <GUID>, if possible, and to make it a permanent link. This allows aggregation to occur when the content changes and there is no duplication of items possible.

If you have any problems with the format of the RSS 2.0 specification, send the message to the email list Rss2-support maintained by Sjoerd Visscher. This mailing list is not a list of technical debates, but a list of technical support for authors and developers when creating and using content in the RSS 2.0 format.

Extension of RSS

RSS originated in the 1999, the goal is to become a simple, easy to understand data format. After it became a popular format, developers wanted to extend it in a namespace using modules, as defined by the consortium.

RSS follows a simple rule that increases its ability. An RSS feed can contain content that is not described on this page, but only those that are defined in one namespace.

The elements defined in this document are not a namespace-specific element of the province, so RSS2.0 is, in a sense, compatible with the original version, that is, a 0.91-or 0.92-version file is also a valid 2.0 version file. If the element of RSS2.0 is in a namespace, then this constraint will be broken, that is, a 0.9x version of the file cannot be a valid 2.0 version of the file.

Development direction

RSS is by no means a perfect format, but it is now very popular and widely supported. To be a fixed specification, RSS takes a long time. The goal of this work is to help RSS become a fixed thing, while promoting and nurturing the growth of the market around it, and paving the way for the new aggregation format. Therefore, for practical purposes, the RSS specification will be frozen in version 2.0.2. The possible versions of 2.0.2 or 2.0.3 that we can expect are just for the purpose of clarifying the specification, rather than adding new features to the format. Subsequent work should focus on modularity, the use of namespaces, and new names in completely new aggregation formats.

License Agreement and author

RSS 2.0 is based on the I-Attribution/share alike Creative Commons License Agreement by the Berkman Center for Internet & Socie Ty at Harvard School offers. The author of this document is the founder of Dave Winer,userland Software and the employee of Berkman Center. (End of full text)