Collabratively defining the data structure

My team need to define the data structure of some feeds that we will be processing. Several people will have input, and will want to make changes to the structures.

I'm after a tool that can be used by the team to make these changes, and both present the data in an easy to understand format and save it as a DTD.

Does such a tool exist? I've found lots of DTD editors, but they all seem geared towards coders rather than the people who know the business rules.

There is a big difference between knowing business rules and knowing how to structure XML. Don't give the managers and executives control of that: leave it to the people who understand XML.

Have your team collect all the business rules as you would normally (hopefully) do, then translate them into a DTD/whatever form yourselves.