One more question.

In forrest.properties i set:

forrest.validate=true
forrest.validate.xdocs=${forrest.validate}
forrest.validate.failonerror=true

Then i edit on site and delete the <header>-Tags. In the docs:
http://forrest.apache.org/dtdx/document-v20.dtdx.html#document

i have understood, that <header> is required. I thought if i switched 
forrest.validate to true, Forrest is going to check if i have the 
required tags on the correct position. But this isn't the case. Am i 
missing something or don't i understand this feature correctly?

Sorry for all the questions, i hope i can contribute something back when 
i have understood all this forrest stuff :-)

Regards,
Chris