- by removing DTDs, remove the concepts of notations and all external resource resolution from the core spec. Also, no possibility of entity-expansion attacks.
- by removing DTDs, remove validation from the core spec.
- merge namespaces into the core specification. At the same time, make them mandatory
- merge the concept of qualified names into the core specification
- by making namespaces mandatory, all the variations of how namespaces get exposed can be eliminated
- merge the info-set definition into the core specification
- by describing XML items and how they relate, implementations can understand what data is relevant at a particular point while parsing the document.
- Merge xml:id into the core specification.
You also had some other fun outlier concepts:
- Eliminate prefixes from infoset. This is mostly a breaking change for XPath and XML Schema.
- Add an explicit qualified name token (possibly recycling the entity declaration). This would allow the above specs to have their functionality restored, although likely with a new format.
- Accept qualified names without prefixes, such as via a {uri}:{localName} syntax.
- remove DTDs completely.
- by removing DTDs, remove non-standard entities
- by removing DTDs, remove the concepts of notations and all external resource resolution from the core spec. Also, no possibility of entity-expansion attacks.
- by removing DTDs, remove validation from the core spec.
- merge namespaces into the core specification. At the same time, make them mandatory
- merge the concept of qualified names into the core specification
- by making namespaces mandatory, all the variations of how namespaces get exposed can be eliminated
- merge the info-set definition into the core specification
- by describing XML items and how they relate, implementations can understand what data is relevant at a particular point while parsing the document.
- Merge xml:id into the core specification.
You also had some other fun outlier concepts:
- Eliminate prefixes from infoset. This is mostly a breaking change for XPath and XML Schema.
- Add an explicit qualified name token (possibly recycling the entity declaration). This would allow the above specs to have their functionality restored, although likely with a new format.
- Accept qualified names without prefixes, such as via a {uri}:{localName} syntax.