The XML Core Working Group has produced two new working draft specifications on namespaces as part of the W3C XML Activity. Namespaces in XML 1.1 is the "first draft of a new 1.1 revision of the Namespaces in XML specification which will incorporate several errata to the 1.0 specification, and will make one substantive change: the provision of a mechanism to undeclare prefixes." Namespaces in XML 1.1 Requirements presents the requirements for the development of Namespaces in XML version 1.1. XML namespaces "provide a simple method for qualifying element and attribute names used in Extensible Markup Language documents by associating them with namespaces identified by URI references." The Requirements document clarifies that the Namespaces in XML 1.1 specification will apply only to XML version 1.1 documents; note that some examples in the WD mistakenly use version 1.0 identifier (<?xml version="1.0"?>) where "1.1" is intended. According to the WG's explanation, the Namespaces in XML 1.0 "has the ability to undeclare the default namespace, but doesn't provide a facility to undeclare namespaces with prefixes; an obvious syntax for such functionality would be an empty namespace attribute value (xmlns:prefix=""); this omission has had adverse consequences on infoset manipulations and serializers." Other specifications negatively affected by the V1.0 limitation include XML-Signature Syntax and Processing, SOAP Version 1.2 part 1: Messaging Framework, XML Inclusions (XInclude) 1.0, XQuery 1.0, and XPath 2.0 and XQuery 1.0 Data Model.
Bibliographic information:
Namespaces in XML 1.1. W3C Working Draft 03-April-2002. Version URL: http://www.w3.org/TR/2002/WD-xml-names11-20020403/. Latest version URL: http://www.w3.org/TR/xml-names11/. Edited by Tim Bray (Textuality), Dave Hollander (Hewlett-Packard Company), Andrew Layman (Microsoft), and Richard Tobin (University of Edinburgh and Markup Technology Ltd).
Namespaces in XML 1.1 Requirements. W3C Working Draft 03-April-2002. Version URL: http://www.w3.org/TR/2002/WD-xml-names11-req-20020403/. Latest version URL: http://www.w3.org/TR/xml-names11-req/. Edited by Jonathan Marsh (Microsoft).
An article "XML Namespaces 1.1" by Leigh Dodds (XML Deviant commentary from XML.com) summarizes a protracted XML-DEV discussion about the new Namespaces WD.
Sean McGrath's article "XML Namespaces" from ITWorld (XML In Practice) opines, in SeanMcGrathian language: "Ostensibly, the namespace Rec is just a simple way of allowing element type names to be globally unique. Unfortunately, in so doing, it introduces rules for defaulting namespaces that significantly complicates any software it touches. XPath, SAX, DOM, XQuery, XSchema, and XSLT -- all of these are caught up in the flapping of the namespace Rec's wings, and it is not a pretty sight! I won't go into the details here, but type any of the previous words into a search engine along with "namespace" and "problem" and you will see what I mean. Recently, the W3C introduced a draft of version 1.1 of the namespace Rec. The changes suggested are minor but have caused the namespace debate to erupt again on xml-dev... When someone as knowledgeable as Joe English starts classifying compliant namespace usage patterns into categories called "neurotic", "borderline", and "psychotic", it behooves us to take a step back and look at what is going on here! When the XML world revisits its fundamentals (around 2008 I suspect as these things always take a decade), namespaces will need to have their wings well and truly clipped in order to redress some of the chaos and damage caused from a decade of inconsiderate flapping. My advice: Don't use namespaces at all if you can avoid it. If you can't, then only put them on the root element. Oh, and don't lend money to anyone who tries to tell you namespaces are simple..."
Principal references:
- Namespaces in XML 1.1. W3C Working Draft 03-April-2002.
- Namespaces in XML 1.1 Requirements. W3C Working Draft 03-April-2002.
- XML 1.1. W3C Working Draft 13-December-2001.
- W3C XML Core Working Group
- W3C XML Activity Statement
- "XML Namespaces 1.1." Commentary on the new W3C WDs, by Leigh Dodds. From XML.com [XML Deviant]. April 10, 2002.
- "XML Namespaces." By Sean McGrath. From ITWorld. April 11, 2002.
- "XML Namespaces." By James Clark.
- XML Namespaces FAQ. Maintained by Ronald Bourret.
- "Namespaces in XML" - Main reference page.