The syndication feeds that FeedBurner produces may include one or more extension elements. Extension elements allow producers (like FeedBurner) to include additional information in RSS and Atom feeds, beyond the capabilities provided by the core RSS or Atom specifications. All of FeedBurner's extension elements are contained in a namespace. (Learn more about extending RSS and Atom feeds.)
This document provides a complete reference for the FeedBurner extension elements. This reference is intended to help developers to validate FeedBurner feeds, but it may also be useful for advanced developers who want to consume FeedBurner feeds.
Note: if you are simply using the FeedBurner service, there is nothing here that you need to know. You do not need to define these elements yourself or worry about their possible values. This document might be interesting if you saw FeedBurner's extension elements in your FeedBurner feed and were wondering what the heck they were. Otherwise, you can safely ignore this guide.
All FeedBurner extension elements are contained in the FeedBurner namespace. This is the FeedBurner namespace:
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http://rssnamespace.org/feedburner/ext/1.0This is how FeedBurner typically defines the namespace at the top of an Atom feed:
<feed xmlns="http://www.w3.org/2005/Atom"
xmlns:feedburner="http://rssnamespace.org/feedburner/ext/1.0">And this is how FeedBurner defines its namespace at the top of an RSS feed:
<rss version="2.0"
xmlns:feedburner="http://rssnamespace.org/feedburner/ext/1.0">You may see other namespaces defined in FeedBurner feeds, because FeedBurner tries to retain extension elements that were defined in the original feed.
FeedBurner feeds may contain any of the following extension elements as children of the root <atom:feed> or <channel> element.
| Cardinality | 0 or 1 |
|---|---|
| Attributes | N/A |
| Value | plain text |
The feedburner:browserFriendly element is simply a human-readable description explaining the concept of syndication feeds. In older browsers, clicking a syndicated feed causes the browser to display a raw XML dump to the end user. This is clearly undesirable, so FeedBurner uses client-side stylesheets to reformat the feed into something more friendly. The content of this element is a message displayed to the end user to explain what they just clicked on.
The value of this element may vary from feed to feed. By default, the value is
This is an XML content feed. It is intended to be viewed in a newsreader or syndicated to another site.
...but publishers can change the message to anything they like, on a per-feed basis.
The feedburner:feedFlare element can appear 0 or 1 times as a child of <atom:feed> or <channel>. The value of this element is plain text, not escaped HTML. Any escaped HTML markup in this element should be displayed as-is, not rendered or interpreted as HTML. Leading and trailing whitespace is significant but may be collapsed to a single space.
| Cardinality | 0 or 1 |
|---|---|
| Attributes | href src |
| Value | plain text |
The feedburner:feedFlare element describes a piece of "flare" that is displayed on the feed's landing page to allow the end user to subscribe to the blog with a variety of online services. If a publisher has created custom BrowserFriendly chicklets and added them to a feed, these chicklets will also appear in the feed as feedburner:feedFlare elements.
The href attribute is a link to a feed subscription service. The src attribute is a link to an image. The element also has text content, which is used as alternate text for the image.
For example, the "Subscribe with Google" flare in the FeedBurner blog's RSS feed looks like this:
<feedburner:feedFlare
href="http://fusion.google.com/add?feedurl=http%3A%2F%2Ffeeds.feedburner.com%2FBurnThisRSS2"
src="http://buttons.googlesyndication.com/fusion/add.gif">
Subscribe with Google
</feedburner:feedFlare>This could be rendered in HTML as
<a href="http://fusion.google.com/add?feedurl=http%3A%2F%2Ffeeds.feedburner.com%2FBurnThisRSS2">
<img src="http://buttons.googlesyndication.com/fusion/add.gif"
alt="Subscribe with Google" />
</a>The href attribute is required. The value of the href attribute is an http or https URI. The URI may be relative. (Consult the specification for the surrounding feed format to determine how to resolve relative URIs.) Leading and trailing whitespace is not significant.
The src attribute is required. The value of the src attribute is an http or https URI. The URI may be relative. Leading and trailing whitespace is not significant.
The feedburner:feedFlare element can appear 0 or more times as a child of <atom:feed> or <channel>. The value of this element is plain text, not escaped HTML. Leading and trailing whitespace is not significant. The value of this element, after stripping leading and trailing whitespace, must not be empty. Each feedburner:feedFlare element in a feed must have a unique href attribute, not counting leading or trailing whitespace, using a byte-for-byte comparison function to establish uniqueness.
| Cardinality | 0 or 1 |
|---|---|
| Attributes | N/A |
| Value | http(s) URI |
As a feed-level element, the feedburner:awareness element points to current basic feed awareness data for the feed. It is only present if the feed publisher has enabled the Awareness API for the feed.
The feedburner:awareness element can appear 0 or 1 times as a child of <atom:feed> or <channel>. The value of this element is an http or https URI. The URI can not be relative. Leading and trailing whitespace is not significant.
| Cardinality | 0 or 1 |
|---|---|
| Attributes | N/A |
| Value | alphanumeric string |
The feedburner:emailServiceId element is a unique identifier for feeds that use the Email Subscriptions service. It is only present if the feed publisher has enabled the Email Subscriptions service.
The feedburner:emailServiceId element can appear 0 or 1 times as a child of <atom:feed> or <channel>. The value of this element is always a non-empty alphanumeric string of any length. The acceptable characters (other than leading and trailing whitespace) are those that match the regular expression [A-Za-z0-9]+. Leading and trailing whitespace is not significant.
Note: XML element names are case-sensitive. The name of this element is feedburner:emailServiceId, not feedburner:emailServiceID.
| Cardinality | 0 or 1 |
|---|---|
| Attributes | N/A |
| Value | http(s) URI |
The feedburner:feedburnerHostname element is the base URI of the site to be used for verifying email subscriptions. It is only present if the feed publisher has enabled the Email Subscriptions service.
The feedburner:feedburnerHostname element can appear 0 or 1 times as a child of <atom:feed> or <channel>. The value of this element is an http or https URI. The URI can not be relative. Leading and trailing whitespace is not significant.
FeedBurner feeds may contain any of the following extension elements as children of any <atom:entry> or <item> element.
| Cardinality | 0 or 1 |
|---|---|
| Attributes | N/A |
| Value | URI |
The feedburner:origLink element points to the original URI of an item. It is only present if the feed publisher has opted to track item clickthroughs.
The feedburner:origLink element can appear 0 or 1 times as a child of <atom:entry> or <item>. The value of this element is a URI. The URI can not be relative. Leading and trailing whitespace is not significant.
| Cardinality | 0 or 1 |
|---|---|
| Attributes | N/A |
| Value | URI |
The feedburner:origEnclosureLink element points to the original URI of an enclosure. It is only present in podcasting feeds, and only if the feed publisher has opted to track enclosure clickthroughs.
The feedburner:origEnclosureLink element can appear 0 or 1 times as a child of <atom:entry> or <item>. The value of this element is a URI. The URI can not be relative. Leading and trailing whitespace is not significant.
| Cardinality | 0 or 1 |
|---|---|
| Attributes | N/A |
| Value | http(s) URI |
As an item-level element, the feedburner:awareness element points to current item awareness data for the item. It is only present if the feed publisher has enabled the Awareness API for the feed.
The feedburner:awareness element can appear 0 or 1 times as a child of <atom:entry> or <item>. The value of this element is an http or https URI. The URI can not be relative. Leading and trailing whitespace is not significant.
| Element name | Child of | Cardinality | Attributes | Value |
|---|---|---|---|---|
| feedburner:browserFriendly | atom:feed, channel | 0 or 1 | N/A | plain text |
| feedburner:feedFlare | atom:feed, channel | 0 or more | href (http(s) URI, required) src (http(s) URI, required) | plain text |
| feedburner:awareness | atom:feed, atom:entry, channel, item | 0 or 1 | N/A | http(s) URI |
| feedburner:emailServiceId | atom:feed | 0 or 1 | N/A | integer > 0 |
| feedburner:feedburnerHostname | atom:feed | 0 or 1 | N/A | http(s) URI |
| feedburner:origLink | atom:entry, item | 0 or 1 | N/A | URI |
| feedburner:origEnclosureLink | atom:entry, item | 0 or 1 | N/A | URI |