Design Goals

  • Must “feel like” DocBook

  • Most existing documents should still be valid or it should be possible to transform them in simple, mechanical ways into valid documents

  • Must enforce as many constraints as possible in the schema. Some additional constraints are expressed with Schematron rules

  • Must simplify many content models

  • Must give users the flexibility to extend or subset the schema in an easy and straightforward way

  • Must allow the generation of a (non-normative) XML DTD and W3C XML Schema.