XDTD as a Simple Validation Language for XML-based Legal Documents

Validation of XML documents is required in order to maintain consistency in large XML document bases, including document bases of legal texts such as acts, judgments, hansards. Current W3C standards for XML validation either do not provide enough precision (DTD) or are too complex to be immediately authored and read by humans (XML Schema). DTD++ has been proposed as an alternative, and relevant legal standards such as Norme In Rete (Italy), Akoma Ntoso (UN for Africa) and CEN Metalex (European CEN standard) are first written in DTD++ and then converted for standard purposes into XML schema and/or DTD. XDTD is a followup of DTD++, and is a shorter and simplified syntax for XML Schema. XDTD combines the power of the XML Schema model with the readability of DTD. The whole set of features of the XML Schema language, including the new ones in the forthcoming 1.1 version of the language, is available in XDTD, while maintaining the same readability and compactness of the original DTD language. In this paper we show how XDTD simplifies the compilation of vocabularies, with attention to legal standards such as the Akoma Ntoso, Norme In Rete and CEN Metalex legal standards.