> the abstract concept behind XML is just to provide a metalanguage for the representation of hierarchical data No it isn't, for the umpteenth time. It is a la

> the abstract concept behind XML is just to provide a metalanguage for the representation of hierarchical data No it isn't, for the umpteenth time. It is a language for marking up text. Markup language deal with grammars - data serialization not data models, and if anything, having regular content models is a more characteristic property for markup languages compared to hierarchy.