xCBL 3.0 XML DTD Version
The XML 1.0 spec provides for the use of XML Document Type Definitions (DTDs), and this type of validation is supported by almost all of the validating XML tools on the market today. xCBL 3.0 is provided in XML DTD form, to allow for it's widest use in XML applications of all types. Needless to say, XML DTDs do not give you the strong typing characteristic of XML Schema languages such as SOX or XDR.
The DTD distribution of xCBL 3.0 includes the entire library of more than 40 message definitions, and all of their components (see the XCBL30.dtd file, which ties together all of the component files). It also has a large online reference guide, which includes the expected message exchange choreographies, and a set of sample documents, which will parse against the XML DTDs using any validating XML parser, or an application that contains one.