Source GUID - RSS2.0 Module

Specification Version: 0.1.0 (DRAFT)

May 2003

This version:


Paolo Valdemarin <>
Matt Mower <>


This specification defines the Source GUID (SGUID) Module for the RSS2.0 syndication format. When an RSS item is posted in response to a previous item (called the source item) RSS 2.0 offers the source element which allows the item to refer to the RSS feed which contains the source item. The SGUID specification provides a more granular approach by offering an sourceRef element which can reference the GUID permalink of the source.


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  1. Status of this document
  2. Purpose
  3. Usage
  4. Elements
  5. Examples
  6. References

Status of this document

This is draft version 0.1 of the SGUID specification. Please send your feedback to either Matt Mower <> or Paolo Valdemarin <>.

Please note that, whilst this specification remains a draft, it is subject to change.


When posting an item to an RSS feed that is in response to a previous item it is useful to be able to reference the previous item. It is common practice to provide the source URL as part of the text of a post (often within a <blockquote> element) however it would be advantageous for software programs processing RSS feeds to be able to access this information (for example to automatically thread posts that reference prior posts). The existing RSS 2.0 source element is inadequate because it only offers the ability to refer to the RSS feed that contained the source item, and not directly to the item itself (i.e. to the permalink of the item).

The SGUID specification offers this functionality via its sourceRef element which should refer to the permalink of the source item.


SGUID is an RSS2.0 module. The elements defined by SGUID are enclosed within a namespace and sent as part of an RSS <item>.


SGUID is an extension to RSS2.0 that works by using additional elements held within a namespace separate from the main RSS elements. By using a namespace, non-SGUID compliant RSS aggregators may safely ignore SGUID elements.

The following is a list of all the SGUID elements used to augment the RSS feed. These elements are intended to be used within the RSS2.0 <item> element.

Namespace Declarations


The sourceRef element specifies a URL that the item wishes to references as a source.

Content Model

    <!ELEMENT sourceRef ( #PCDATA ) >




The sourceRef element contains a URL indicating a source URL reference.


The following are examples of using SGUID to associate items with URL's. It has been assumed that the sguid namespace has been declared in the <rss> element:


        <title>A sample item</title>
        <description>A sample item</description>

A sample feed is available.


ID attribute
Refers to the ifragment production in the IRI draft specification
XML 1.0 (2nd edition)
Resource Description Framework
XML Topic Maps
eXtensible Faceted Markup Language
Outline Processor Markup Language
Uniform Resource Identifiers (URI): Generic Syntax
RSS Web Syndication Format 0.92
RDF Site Summary 1.0
Really Simple Syndication 2.0