DFDL infoset allows characters the XML infoset doesn't ... how can that be?

[Costello, Roger L.]

Hello DFDL community,

Someone told me this:

DFDL's infoset allows characters
the XML infoset doesn't.

What characters?

How can it be? After all, well-formed XML is generated. And, the DFDL schema is 
well-formed XML. Right?

/Roger