Grouping Documents into Classes

Making the Implicit Explicit

Current Situation Strictly speaking, there is no concept of document classes in XML 1.0. Documents may share external resources - DTDs, entities, stylesheets, etc. - but this is on a document-by-document basis.
Potential Grouping documents into classes centralizes control over document structures and presentation, simplifying large-scale changes. Applications could identify which document classes they were prepared to work with, and document classes could identify processors in which they could not be reliably opened.
Drawbacks This approach would make it difficult for documents to be different where that is appropriate. (Styles are an easy override, but the rest is hard.)