Other Approaches

  • It might be technically possible to achieve some of the goals using DTDs simply by refactoring the parameter entities (again).

  • W3C XML Schema would be better than DTDs.

    • I’m not sure the abstraction is right for schemas with lots of mixed content.

    • Determinism would still be a problem.

    • Local element declarations force customizations to “cascade” up the tree.

    • No support for co-constraints.

  • Schematron could do it all, but it would require a lot of rules.