Re: B.13 ENTITY attributes for notations?

> B.13 Should XML remove SGML's prohibition on ENTITY attributes for
> notations (11.4.1)?

It's funny -- I came across this yesterday, as SoftQuad Panorama actually
uses ENTITY notation attributes in its style sheet DTD (oops).

They're used to specify a mask for an icon.

I don't understand the restriction in SGML (maybe someone can explain it?)
but I don't see how it can sensibly be lifted in XML unless it might also
be lifted in SGML.