https://www.rssboard.org/rss-autodiscovery
RSS Advisory Board
RSS Autodiscovery
Editor's Note: This is version 1.0 of this document, published Nov.
27, 2006.
1. Introduction
RSS autodiscovery is a technique that makes it possible for browsers
and other software to automatically find a site's RSS feed, whether
it's in RSS 1.0 or RSS 2.0 format.
Supported by Mozilla Firefox 2.0, Microsoft Internet Explorer 7.0 and
other browsers, autodiscovery has become the best way to inform users
that a web site offers a syndication feed. When a browser loads a
page and discovers that a feed is available, Firefox and Internet
Explorer display the common feed icon in the address bar.
Firefox address bar of page with RSS feed identified using RSS
Autodiscovery
Users can click the icon to subscribe with the browser's RSS reader
or the user's preferred reader. Web publishers who offer feeds reach
a wider potential audience with autodiscovery.
This specification describes how web publishers can support
autodiscovery by adding an HTML header to web pages.
2. Conventions
In this documentation, the key words may, must, must not, optional,
recommended, required, shall, shall not, should and should not are to
be interpreted as described in RFC 2119.
3. link Element
Autodiscovery employs the link element from HTML and XHTML to
identify a site's syndication feed. The link must be placed within a
web page's head element to establish a relationship between the page
and another document.
To support autodiscovery, a link element must be added to the header,
as shown in this HTML markup from The RSS Blog:
The RSS Blog
The link can be placed within the header of the site's home page,
individual pages such as weblog entries and any other page where a
user might want to know that a feed's available. A head may include
more than one autodiscovery link, but each must identify a different
feed.
To make the RSS subscription process simple for inexperienced users,
publishers should include only one autodiscovery link per page, using
it to identify a site's main feed.
If you decide to include more than one autodiscovery link, the first
link should be the site's main feed.
Publishers who offer the same feed content in several syndication
formats should not use autodiscovery links for all of them. Choosing
only one feed format for autodiscovery makes it easier on new
subscribers, especially if they are unfamiliar with syndication and
can't distinguish between the Atom, RSS 1.0 and RSS 2.0 formats.
The link element must have three attributes that describe the
relationship: href, rel and type and may have a title attribute.
Because attribute names must be lowercase in XHTML, autodiscovery
link attributes should have lowercase names in HTML as well.
3.1. href Attribute
The href attribute must be the feed's URL. This can be a relative URL
in pages that include a base element in the header.
RSS Advisory Board
Because some software might not check for a base URL in relation to
autodiscovery links, publishers should identify feeds with full URLs.
When an autodiscovery link is relative and no base URL has been
provided, clients should treat the web page's URL as the base.
3.2. rel Attribute
The rel attribute must have a value of "alternate", a keyword that
indicates the link is an alternate version of the site's main
content.
Although for purposes other than autodiscovery this attribute may
contain multiple keywords separated by spaces, in an autodiscovery
link, the value must not contain keywords other than "alternate".
Additionally, though rel keywords are case-insensitive elsewhere,
"alternate" must be lowercase.
3.4. title Attribute
The title attribute, when present, contains be a short,
human-readable label such as the site's name or the feed's name. When
a page contains more than one autodiscovery link, the title enables
users to differentiate between the feeds, as demonstrated by Om
Malik's GigaOM site.
Firefox address bar of page with multiple RSS feeds identified using
RSS Autodiscovery
Each autodiscovery link has a different title, which Mozilla Firefox
displays in a drop-down menu when a user clicks the common feed icon.
3.3. type Attribute
The type attribute must contain the feed's MIME type, which is
"application/rss+xml" for RSS 1.0 or RSS 2.0 feeds.
Although type values are case-insensitive for other HTML and XHTML
links, the value must be lowercase for autodiscovery.
4. License
Copyright 2006 RSS Advisory Board. Redistribution and reuse of this
document is permitted under the terms of the Creative Commons
Attribution-ShareAlike 2.0 license.
5. Credits
Rogers Cadenhead, James Holderness and Randy Charles Morin
contributed to this document. Comments and corrections regarding this
document are encouraged on the RSS-Public mailing list.
Main Menu
RSS Advisory Board
RSS Specification
RSS Profile
RSS Validator
RSS Autodiscovery
Board Members
Charter
RSS-Public Mailing List
RSS Language Codes
RSSCloud Interface
RSS History
RSS Feeds
Subscribe to Really Simple Syndication This Weblog
Spec Library
Current
2.0.1
2.0
0.92
0.91 (UserLand)
0.91 (Netscape)
0.90
RSS Change Notes
Namespaces
Creative Commons
Media RSS
Trackback
Archive
Site Index
SkipHours and SkipDays
RSS Encoding Examples
Articles
Board Members
Rogers Cadenhead
Sterling "Chip" Camden
Simone Carletti
James Holderness
Jenny Levine
Eric Lunt
Randy Charles Morin
Ryan Parman
Jake Savin
Jason Shellen
Paul Querna
Other Formats
Atom
RDF Site Summary
RSS Advisory Board | RSS Feed | RSS Specification | Hosted by
Workbench