[XML-SIG] DTD internal subset with Amara?

[Brock Filer]

I've gone as far as my brain can take XSL, and so started experimenting 
with Amara.
It's wonderful, but is there some way I can use it to output an 
internal DTD subset? I need it to declare certain attributes as IDs and 
IDREFs for subsequent xsl processing. I know I could reference an 
external DTD, but I prefer to keep that important data in the document, 
more robust that way. So I'm just sticking it in the file as a string. 
But that's hackish, and also means that my script needs to know the 
internal subset. I'd like to be able to just duplicate the declaration 
from the input document to the output doc.