Use of version-specific public ids for DTD module entity inclusions

["Yas Etessam" <yas.etessam@xmetal.com>]

Hi all,

Here is one more feature request around versioning and the DTDs. 

All of the entities included in DITA's DTDs use version-less public ids.
A catalog and processor may resolve the following entity, but it is not
possible to later be able to distinguish this entity inclusion as DITA
1.0, 1.1 or 1.2.  

<!ENTITY % topic-type   PUBLIC  "-//OASIS//ELEMENTS DITA Topic//EN"
"topic.mod" >
%topic-type;

If the entity include for topic.mod was re-written like this, we
wouldn't have multiple entities sharing the same public id:
 <!ENTITY % topic-type   PUBLIC  "-//OASIS//ELEMENTS DITA 1.1 Topic//EN"
"topic.mod" >                                                

%topic-type;

XMetaL's development team feature request is that DITA DTD sets provide
versioned public ids for the DTD entity inclusions.   The high level use
case for this request is that it will help enable side-by-side editing
of different versions of DITA documents. 

Regards,

Yas Etessam