Where is the DTD?

In some of the older mails of this list, someone mentioned a DTD for
SVN's delta descriptions. I looked around in the CVS tree, but
unfortunately cannot find it there. At least for me, it would be nice
to have a DTD for

- (right now my own) educational purposes,
- validation of syntactical correctness of delta descriptions as a
  kind of debugging, and
- documentation and reference purposes.

Is someone out there who maintaines or simply has a copy of the DTD?

-- 
Jens Klöcker <jens@kloecker.org> | Co-existence or no existence.