The World Wide Web Consortium (W3C) this week released the first public working drafts of the XML Schema specification, suitably called XML Schema Part 1: Structures, and XML Schema Part 2: Datatypes.
The W3C published these working drafts to ensure that the public can follow the XML Schema design work, so that the final result will be widely accepted and adopted.
XML Schema Part 1: Structures proposes the mechanisms for associating datatypes with XML element types and attributes, enabling XML software to do a manage dates, numbers, and other special forms of information. XML Schema Part 2: Datatypes proposes the methodology of describing the structure and constraining the contents of XML documents.
The Resource Description Framework (RDF) was created to integrate different types of Web-based metadata activities, such as content ratings, search engine data collection, and digital library collections. Schemas, on the other hand, will enable software to distinguish the data governed by industry-standard and vendor-specific schemas, and help applications know when it is OK to ignore information it doesn’t understand, and when it should not do so.
Right now, the rules about what kinds of information can appear in an XML
document can only be expressed in the form of XML document type definitions (DTDs). Developers have found that there are some common rules which cannot be expressed in DTD form. XML Schemas will be able to express some of the rules that DTDs cannot express. XML schemas are actually XML documents themselves. By using XML as the document format for schemas, users and developers of XML schemas will be able to use standard XML tools.
For additional information about the W3C’s XML Schema work, read the W3C’s XML Activity statement.