After all the discussion about "What is data?" I don't know if this list is the place to discuss actual details of implementation, but please feel free to send me elsewhere if you can think of a better venue.

I have a need to handle XML that references a non-existent DTD.  The DTD is irrelevant to the actual processing of the XML, and isn't available anywhere, but it is declared in in the DOCTYPE.  I'm sure many of you have encountered this situation: it's practically the norm, in my experience.

After years of dealing with this inherently unsatisfactory situation in a variety of ways, I came up with a new one that I am liking at the moment, which is to insert a Stream into a Java XML processing stack that strips out the prolog of the XML document before handing it off to a parser.  This has the nice property that it doesn't require modifications to the stored XML files.  It loses PIs and comments and the XML decl, but I can live with that.