Re: Entity Ignorance

>And how is this compatible with SGML?  

SGML does not prescribe error recovery mechanisms for references to
undeclared entitie, and one possible recovery strategy is to look for
the entity using the name of entity:

  <?XML VERSION="1.0">

would result in a search for an entity named "bar", perhaps by looking
in a catalog, relative to the referring entity, etc.

I think this may end up being *more* robust in some ways, because people
will have to implement a default behaviour for cases where entities 
are not declared, which they otherwise may not have to.

This will also make it easier to parse entities in isolation.