The World Wide Web Consortium (W3C) has recommended its XML (Extensible Markup Language) Schema as a candidate to become a standard.

The W3C is inviting Web professionals to implement the XML Schema, run the code and provide feedback.

Michael Sperberg, co-chair of the XML Schema working group, said: "The schema is ready to implement, and we are looking for feedback. It's stable, and the only changes that would be introduced now are the result of implementation feedback."

Essential changes The code isn't finalized yet, but McQueen explained only essential changes will be made – new features will be saved for the final version.

The schema is a way of describing XML documents that follow DTDs (Document Type Definitions), although DTDs will not disappear.

The XML Schema proposals consists of three parts. One part defines a set of simple datatypes, which can be associated with XML-element types and attributes. This allows XML software to do a better job of managing dates, numbers, and other special forms of information.

Structure The second part of the specification proposes methods for describing the structure and delimiting the contents of XML documents. It also defines the rules governing schema-validation of documents. The third part is a primer, which explains what schemas are, how they differ from DTDs, and how someone builds a schema.

The W3C claims that the schema has a number of advantages over DTDs. Schemas enable XML and XML software packages to describe data types, use XML name spaces, allow developers to take advantage of inheritance, and are actual XML documents - unlike DTDs.

The next step after a candidate recommendation is made is to publish a proposal recommendation, and then finally to recommend its ratification as a standard by the W3C.

More detail about the candidate Web standard is available from W3C'sWeb site.