<
is a fundamental entity defined in the XML specification itself; é
isn't. That's why you're seeing the difference in behaviour. (So I'd expect &
, >
, '
and "
to work too.) See http://www.w3.org/TR/REC-xml/#sec-references
I don't think the XmlResolver
is particularly relevant here as your XML doesn't refer to any other DTDs etc. I don't think it's meant to be used to automatically import entities without referring to anything at all within the document itself.