Why is <shortdesc> defined twice ?

[Jang <jang@jang.nl>]

While finishing my customise DITA plugin for FrameMaker, I found an inconsistency. I assumed that every element in DITA is unique, has a unique name and can be traced to one single location where it is defined. I am running into problems with <shortdesc> as this seems to be the only exception to the no copy no paste rule. This element is defined in topicMod as well as in mapMod. While it is probably true that maps and topics will never be combined into a single DITA file, I believe this is a design flaw that should be corrected in DITA 2.0. 

As I understand it, commonElementsMod is the place to define elements that are shared between topics and maps. This means that <shortdesc> should be moved there. The only difference between the two <shortdesc> elements is their @class, which points either to the topic or the map module to which the element belongs. I do not see any valid reason why this is the case. After all, the elements in commonElementsMod are also included in the map while still having their @class point to the topic.

I believe that avoiding ambiguity is more important than the convenience of having the same element appear in two different modules. Automation based on non-ambiguous materials is much easier than having to include specific disambiguation code for one DITA element. We are not copying any of the other elements, AFAIK.

Jang F.M. Graat
Smart Information Design
Amsterdam, Netherlands
Cell: +31 646 854 996