RSS Tutorial for Content Publishers and Webmasters
for Content Publishers and Webmasters
This tutorial explains the features and benefits of a Web
format called RSS, and gives a brief technical overview of it. The reader is
assumed to have some familiarity with XML and other Web technologies. It is
not meant to be exhaustive; for more information, see the 'More Information about RSS' section.
- Introducing RSS
- What's in a RSS feed?
- How do people use feeds?
- Why should I make an RSS feed available?
- But isn't that giving away my content?
- Choosing Content for RSS Feeds
- Publishing RSS
- Telling People About Your Feed
- RSS Versions and Modules
- RSS 0.9x
- RSS 1.0
- Dublin Core Module
- Tips for Generating Good RSS Feeds
- RSS Tools and Validators
- Aggregators and other RSS Clients
- More Information about RSS
- About this Document
Think about all of the information that you access on the Web on a
day-to-day basis; news headlines, search results, "What's New", job
vacancies, and so forth. A large amount of this content can be thought of as
a list; although it probably isn't in HTML
the information is list-oriented.
Most people need to track a number of these lists, but it becomes
difficult once there are more than a handful of sources. This is because they
have to go to each page, load it, remember how it's formatted, and find where
they last left off in the list.
RSS is an XML-based format that allows the syndication
of lists of hyperlinks, along with other information, or metadata,
that helps viewers decide whether they want to follow the link.
RSS allows peoples' computers to fetch and understand the information, so
that all of the lists they're interested in can be tracked and personalized
for them. It is a format that's intended for use by computers on behalf of
people, rather than being directly presented to them (like HTML).
To enable this, a Web site will make an RSS feed, or channel,
available, just like any other file or resource on the server. Once a feed is
available, computers can regularly fetch the file to get the most recent
items on the list. Most often, people will do this with an
aggregator, a program that manages a number of lists and presents
them in a single interface.
RSS can also be used for other kinds of list-oriented information, such as
syndicating the content itself (often weblogs) along with the links.
However, this tutorial focuses on the use of RSS for syndication of links.
What's in a RSS feed?
A feed contains a list of items, each of which is identified by a link.
Each item can have any amount of metadata associated with it.
The most basic metadata supported by RSS includes a title for the link and
a description of it; when syndicating news headlines, these fields might be
used for the story title and the first paragraph or a summary, for example.
For example, an simple item might look like;
<description>The earth was attacked by an invasion fleet
from halfway across the galaxy; luckily, a fatal
miscalculation of scale resulted in the entire armada
being eaten by a small dog.</description>
Additionally, the feed itself can have metadata associated with it, so
that it can be given a title (e.g., "Bob's news headlines"), description, and
other fields like publisher and copyright terms.
For an idea of what full feeds look like, see 'RSS
Versions and Modules'.
How do people use feeds?
Aggregators are the most common use of RSS feeds, and there are several
types. Web aggregators (sometimes called portals) make this view available in
a Web page; my Yahoo is a well-known
example of this. Aggregators have also been integrated into e-mail clients,
users' desktops, or standalone, dedicated software. See 'Aggregators and other RSS Clients' for more
Aggregators can offer a variety of special features, including combining
several related feeds into a single view, hiding items that the viewer has
already seen, and categorizing feeds and items.
Other uses of RSS feeds include site tracking by search engines and other
software; because the feed is machine-readable, the search software doesn't
have to figure out which parts of the site are important and which parts are
just the navigation and presentation. You may also choose to allow people to
republish your feeds on their Web sites, giving them the ability to represent
your content as they require.
Why should I make an RSS feed available?
Your viewers will thank you, and there will be more of them, because RSS
allows them to see your site without going out of their way to visit it.
While this seems bad at first glance, it actually improves your site's
visibility; by making it easier for your users to keep up with your site -
allowing them to see it the way they want to - it's more likely that they'll
know when something that interests them is available on your site.
For example, imagine that your company announces a new product or feature
every month or two. Without a feed, your viewers have to remember to come to
your site and see if they find anything new - if they have time. If you
provide a feed for them, they can point their aggregator or other software at
it, and it will give them a link and a description of developments at your
site almost as soon as they happen.
News is similar; because there are so many sources of news on the
Internet, most of your viewers won't come to your site every day. By
providing an RSS feed, you are in front of them constantly, improving the
chances that they'll click through to an article that catches their eye.
But isn't that giving away my content?
No! You still retain copyright on your content if you wish to.
By supplying an RSS feed, you can control what information is syndicated
in the feed, whether it's a full article or just a teaser. Your content can
still be protected by your current access control mechanisms; only the links
and metadata are distributed. You can also protect the RSS feed itself with
SSL encryption and HTTP username/password authentication too, if you'd
In many ways, RSS is similar to the subscription newsletters that many
sites offer to keep viewers up-to-date. The big difference is that they don't
have to supply an e-mail address, lowering the barrier of privacy concerns,
while still giving you a direct channel to your viewers. Also, they get to
see the content in the manner that's most convenient to them, which means
that you get more eyes looking at your content.
Choosing Content for RSS Feeds
Any list-oriented information on your site that your viewers might be
interested in tracking or reusing is a good candidate for an RSS feed. This
can encompass news headlines and press releases, job listings, conference
calendars and rankings (like 'top 10' lists).
- News & Announcements - headlines, notices and any
list of announcements that are added to over time
- Document listings - lists of added or changed pages,
so that people don't need to constantly check for different content
- Bookmarks and other external links - while most people
use RSS for sharing links from their own sites, it's a natural fit for
sharing lists of external links
- Calendars - listings of past or upcoming events,
deadlines or holidays
- Mailing lists - to compliment a Web-based archive of
public or private e-mail lists
- Search results - to let people track changing or new
results to their searches
- Databases - job listings, software releases, etc.
While it's a good start to have a 'master feed' for your site that lists
recent news and events, don't stop there. Generally, each area of your site
that features a changing list of information should have a corresponding
feed; this allows viewers to precisely target their interests.
For example, if your news site has pages for World news, national news,
local news, business, sports, etc., there should be a feed for each of these
If your site offers a personalized view of data (e.g., people can choose
categories of information that will show up on their home page), offer this
as a feed, so that the viewers' Web pages match the content of their
A great example of this is Apple's
Music Store RSS feed generator; you can customize it based on your
preferences, and the views it allows match those provided in the Music
Finally, remember that feeds are just as - if not more - useful on an
Intranet as they are on the Internet. RSS can be a powerful tool for sharing
and integrating information inside a company.
There are a number of ways to generate a feed from your content. First of
all, explore your content management system - it might already have an option
to generate an RSS feed.
If that option isn't available, you have a number of choices;
- Self-scraping - The easiest way to publish a feed from
existing content. Scraping tools fetch your Web page and pull
out the relevant parts for the feed, so that you don't have to change
your publishing system. Some use regular expressions or XPath
expressions, while others require you to mark up your page with minimal
hints (usually using <div> or <span> tags) that help it
decide what should be put into the feed.
- Feed integration - If your site is dynamically
generated (using languages like Perl, Python or PHP), it may have a RSS
library available, so that you can integrate the feed into your
- Starting with the feed - Alternatively, you can manage
the list-oriented parts of your content in the RSS feed itself, and
generate your Web pages (as well as other content, like e-mail lists)
from the feed. This has the advantage of always having the correct
information in the feed, and tools like XSLT make this option easy,
especially if you're starting from scratch.
- Third party scraping - If none of these options work
for you, some people on the Web will scrape your site for you and make
the feed available. Be warned, however, that this is never as reliable or
accurate as doing it yourself, because they don't know the details of
your content or your system. Also, using third parties introduces another
point of failure in the delivery process; problems there (network, server
or business) will cause your feed to be unavailable.
For more information about all of these options, see "Tools for generating and validating RSS feeds" and "More Information about RSS".
Telling People About Your Feed
An important step after publishing a feed is letting your viewers know
that it exists; there are a lot of feeds available on the Web now, but it's
hard to find them, making it difficult for viewers to utilize them.
Pages that have an associated RSS feed should clearly indicate this to
viewers by using a link containing like 'RSS feed'. For example,
<a type="application/rss+xml" href="feed.rss">RSS feed for this page</a>
where 'feed.rss' is the URL for the feed. the 'type' attribute tells
browsers that this is a link to an RSS feed in a way that they understand.
Additionally, some programs look for a link in the <head> section of
your HTML. To support this, include a <link> tag;
<link rel="alternate" type="application/rss+xml"
href="feed.rss" title="RSS feed for My Page">
These links should be placed on the Web page that is most similar to the
feed content; this enables people to find them as the browse.
Finally, there are a number of guides and registries for RSS feeds that
people can search and browse through, much like the Yahoo directory for Web
sites; it's a good idea to register your feed. See "Related Resources" for
RSS Versions and Modules
There are two main versions of the RSS format in use today; RSS 0.9x and
RSS 1.0. Although the numbers might lead you to believe that 1.0 replaces
0.9x, both are being actively used and developed. Each version has its
benefits and drawbacks; RSS 0.9x is known for its simplicity, while RSS 1.0
is more extensible and fully specified. Both formats are XML-based and have
the same basic structure.
People tend to get into heated discussions about the better format.
Ultimately, it's a choice you shouldn't worry too much over; good RSS tools
and aggregators will understand both formats. This section presents a quick
overview of each; for more information, see their specifications and
RSS 0.9x (the 'x' is for the last digit; as of writing, RSS 0.94 is in
development) was designed by Netscape Communications and UserLand software,
and is championed by UserLand's Dave Winer. In this version, RSS stands
for "Really Simple Syndication," and simplicity is its focus.
This branch of RSS is based on RSS 0.91, which was first on MyNetscape
documented at Netscape and later refined by Userland.
Included in http://backend.userland.com/rss092 - the
latest stable version - are channel metadata like
allows you to specify a thumbnail image to display with the feed);
managingEditor, to identify who's
responsible for the feed, and
lastBuildDate, which shows when
the feed was last updated. Items have the standard
well as other, more experimental facilities like
which allows attachments to be automatically downloaded (don't expect these
features to be supported by all aggregators, however).
RSS 0.9x takes a versioned approach to extensibility; new features are
added by declaring a new version of RSS in the 0.9 series. Winer controls the
release of new versions, so if you have suggestions about the future of RSS
0.9x, it's best to talk to him.
Here's an example of a minimal RSS 0.9x feed:
<description>My example channel</description>
<title>News for September the Second</title>
<description>other things happened today</description>
<title>News for September the First</title>
RSS 1.0 stands for "RDF Site Summary." This flavor of RSS incorporates
RDF, a Web standard for
metadata. Because RSS 1.0 uses RDF, any RDF processor can understand RSS
without knowing anything about it in particular.
RSS 1.0 also uses XML
Namespaces to allow extensions - called RSS Modules - to be
added without worrying about conflicts. This is because RSS 1.0 doesn't use a
central person for extending the format; instead, namespaces are used to
describe a space for your own extensions. For example, if you had an ISBN
module to track books, it might look like this;
Generally, though, you should look for available RSS Modules, rather than
defining your own, unless you're sure that what you need doesn't exist.
RSS 1.0 feeds look very similar to RSS 0.9x feeds, with a few key
- The entire feed is wrapped in
</rdf:RDF> elements (so that processors know that it's
<item> has an
that usually, but not always, matches the
assigns an identifier to each item
- There's an
<items> element in the channel metadata
that contains a list of items in the channel, so that RDF processors can
keep track of the relationship between the items
- Some metadata uses the
rdf:resource attribute to carry
links, instead of putting it inside the element.
RSS 1.0 is developed and maintained by an ad hoc group of interested
people; see their Web site for http://web.resource.org/rss/1.0/ more
information about RSS 1.0 and RSS Modules. See below for an example of an
RSS 1.0 feed.
Dublin Core Module
The most well-known example of an RSS Module is the
Dublin Core is a set of metadata developed by librarians and
information scientists that standardizes a set of common metadata that is
useful for describing documents, among other things. The Dublin Core Module
uses these metadata to attach information to both feeds (in the channel
metadata) and to individual items.
This module includes useful elements like
associating dates with items,
dc:subject, which can be useful
for categorizing items or feeds, and
dc:rights, for dictating
the intellectual property rights associated with an item or a feed.
Here's an example of a minimal RSS 1.0 feed that uses the Dublin Core
<description>My example channel</description>
<title>News for September the First</title>
<description>other things happened today</description>
<title>News for September the Second</title>
As you can see, RSS 1.0 is a bit more verbose than 0.9x, mostly because it
needs to be compatible with other versions of RSS while containing the markup
that RDF processors need.
Tips for Generating Good RSS Feeds
RSS is easy to work with, but like any new format, you may encounter some
problems in using it. This section attempts to address the most common issues
that arise when generating a feed.
- Meaningful Links - Give every item in your feed a
distinct URL in the
<link> tag, so that software can
tell the difference between items, and recognize items that it's already
seen. If two items really point at the same page, you can use different
- Meaningful Metadata - Try to make the metadata useful
on its own; for example, if you only include a short
<title>, people may not know what the link is about.
By the same token, if you shove an entire article into
<description>, it'll crowd people's view of the feed,
and they're less likely to stay interested in what you have to say.
Generally, you want to put enough into the feed to help someone decide
whether they should follow the link.
- Encoding HTML - Although it's tempting, refrain from
including HTML markup (like
<p>) in your RSS feed;
because you don't know how it will be presented, doing so can prevent
your feed from being displayed correctly. If you need to include a a tag
in the text of the feed (e.g., the title of an item is "Ode to
<title>"), make sure you escape ampersands and angle brackets (so
that it would be "Ode to <title>").
- XML Entities - Remember that XML doesn't predefine
entities like HTML does; therefore, you won't have
© and other common entities
available. You can define them in the XML, or alternatively just use an
character encoding that makes what you need available.
- Character Encoding - Some software generates feeds
using Windows character sets, and sometimes mislabels them. The safest
thing to do is to encode your feed as UTF-8 and check it by parsing it
with an XML parser.
- Version Compatibility - RSS 1.0 generators need to
take special steps to ensure compatibility with 0.9x parsers; most
importantly, use the default namespace for RSS. See the 1.0 spec for more
- Communicating with Viewers - Don't use items in your
feed to communicate to your users; for example, some feeds have been
known to use the
<description> to dictate copyright
terms. Use the appropriate element or module.
- Communicating with Machines - Likewise, use the
appropriate HTTP status codes if your feed has relocated (usually,
301 Moved Permanently) or is no longer available (
404 Not Found).
- Making your Feed Cache-Friendly - Successful RSS feeds
see a fair amount of traffic because clients poll them often to see if
they've changed. To support the load, Web Caching can help; see the caching tutorial.
This is an incomplete list of tools for creating RSS feeds, and checking
them to make sure that you've done so correctly. Note that there are many
more libraries that help parsing RSS; these haven't been included here
because this tutorial focuses on the Webmaster, not consumers of RSS.
- A Perl module for generating and parsing RSS.
RSS - Work with feeds as a collection of nodes; support for
Python, Perl and C.
- Site Summaries
in XHTML - An online service (also available as an XSLT
stylesheet) that uses hints in your HTML to generate a feed.
RSS 1.0 Validator - Check your 1.0 RSS feeds; includes
module support. From Leigh Dodds.
Aggregators and Other RSS Clients
This is an incomplete listing of aggregators and other consumers of RSS
content. For more, see "More Information about
- http://www.ariadne.ac.uk/issue35/miller - Syndicated content -
Good list of best practices for creating an RSS feed.
- http://rssgov.com/rssworkshop.html - RSS Workshop -
A well-regarded introduction to publishing RSS feeds, from the state of
Utah Online Services division.
- http://blogspace.com/rss/ -
Lists aggregators, toolsets and RSS-related news.
- http://www.oreillynet.com/rss/- RSS
Devcenter - O'reilly's Web portal for all things RSS.
About this Document
This document is Copyright Â©2002 Mark Nottingham. It may be freely
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Version 0.83 -- May 22, 2004
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