Major Description
The struts-config and tiles-config dtds are published as part of the top-level website at http://struts.apache.org/dtds . These currently require manual updates when a change is made.
Use the antrun plugin and the 'get' task to retrieve the lates dtds from the Subversion repository each time the site is published.
(The dtds are also published under http://struts.apache.org/1.x/dtds so that they will be included in the distribution.)