The VO-DML metamodel groups Attributes, Composition and References within ObjectTypes and DataTypes - it would be easier to process if this grouping restriction were removed - it would also potentially make the models defined more aesthetically pleasing as the declaration order would be preserved.
The metamodel could use an xsd:choice to do this - the change would be backwards compatible.
The VO-DML metamodel groups Attributes, Composition and References within ObjectTypes and DataTypes - it would be easier to process if this grouping restriction were removed - it would also potentially make the models defined more aesthetically pleasing as the declaration order would be preserved.
The metamodel could use an xsd:choice to do this - the change would be backwards compatible.