Creative Commons Namespace for RSS and Atom

Creative Commons Namespace for RSS at Atom

Editor's Note: This document was published on June 23, 2023.

1. Introduction

Creative Commons (CC) is a set of licenses that enable the free distribution of an otherwise copyrighted work such as a book, web page or technical document. A CC license is used when an author wants to allow other people to share, use or build upon a work that the author has created. CC provides an author flexibility in what rights are being granted. For example, they might choose to allow only non-commercial uses of a given work or allow only uses of a work that are attributed to reflect the original author. CC licenses offer protection for the people who reuse or redistribute an author's work from concerns of copyright infringement as long as they honor the conditions specified in the license under which the work is distributed.

The cofounder of Creative Commons, Harvard Law School professor Lawrence Lessig, explained the rationale for the licenses this way:

Creators who want to say 'All Rights Reserved' need not apply. But creators who want just 'Some Rights Reserved' could use our licenses to express that idea simply. And individuals and institutions that wanted to use work they've found on the Internet could do so without fearing they would be confused with those who believe in 'No Rights Respected' when it comes to copyright.

The Creative Commons namespace enables a feed in RSS 2.0 or Atom format to indicate the copyright license that applies to an entire feed or one or more specific items in that feed. Though the namespace takes its name from the Creative Commons set of content-sharing licenses, it is not limited to just these license. It potentially may be used with other licenses.

Creative Commons has made available multiple licenses that could be applied to the contents of an RSS or Atom feed.

An XML namespace is declared in the top-level element of the document and must consist of the text "xmlns:" followed by the namespace name, an equal sign, and a URL that uniquely identifies the namespace. The Creative Commons namespace requires a declaration with the URL "http://backend.userland.com/creativeCommonsRssModule" in the top-level element, as in this example for RSS:

A sample feed demonstrates how to incorporate elements from this namespace in an RSS 2.0 feed.

The URL of the namespace does not have to resolve to a web page. The namespace name does not have to be "creativeCommons", but the name that is used in the declaration must also be used throughout the feed in elements that belong to the namespace.

To check whether a feed correctly implements the Creative Commons namespace, use the RSS Validator for RSS and the Feed Validator for Atom.

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 according to the guidelines in RFC 2119.

3. Channel License

The license element, when present in an RSS channel or Atom feed element, indicates that all of the feed's content has been made available under a copyright license (optional). The element's value must be a URL that identifies the license, as in this example:

<creativeCommons:license>https://creativecommons.org/licenses/by-nc-sa/2.5/</creativeCommons:license>

A channel may contain more than one license element to indicate its availability under additional licenses.

4. Item License

The license element, when present in an RSS item or Atom entry element, indicates that the item is available under a copyright license (optional).

The element's value must be a URL that identifies the license, for example:

<creativeCommons:license>https://creativecommons.org/licenses/by-sa/2.5/</creativeCommons:license>

An item may contain more than one license element to indicate its availability under additional licenses. An RSS license element in item takes precedence over an RSS license element in item and an Atom license element in entry takes precedence over an Atom license element in feed.