I have created a wml-based markup language and have defined it through a set
of XSD documents.

When I open my XSD docs in XML Spy, I can see that there are already 5
entities defined (amp, apos, gt, lt, quot). I don't know where these
entities are defined. They are not defined in my own XSDs.

I need to extend the set of supported entities to include some extra special
characters required by my markup language - nbsp, shy, euro etc.

1) where are the existing entity definitions coming from?
2) how can I add some new entity definitions?

So far I have been using an internal DTD subset in my instyance docs to
allow validation of entity references of my instance documents. This is an
ugly/clumsy solution. I would much rather use entity references within my
XSD to achieve validation of my instance files.

I have included a sample instance doc which points to a published XSD in its
xmlns attributes.

Thanks in advance,

Richard Foxworthy