xmllink conformance

There is certainly a lot in this spec.  And the way is left free
for xmllink apps to handle linking by other means, too.  If I am
to publish XML docs (or perhaps more properly XML+xmllink docs),
I'll probably want to know whether the requesting app can handle
the specified linking mechanisms - or else the requesting app
will need to be able to discover what linking mechanisms are used - 
in the likely case that not all apps can handle all possible

So I think this spec needs a conformance section indicating what
an xmllink-spec-compliant xmllink app MUST do.  (There is a recent
RFC on vocabulary for conformance.)  In what I see here, only
negative conformance is indicated (for the TITLE, BEHAVIOR,
and RENDER atts).

A related issue is that interdependence of att values is
specified ("If the reference type is TEI, the HREF must be
a TEI locator"), but this cannot be determined by SGML parsing;
is an xmllink supraSGML syntax checker contemplated?

    Terry Allen    Fujitsu Software Corp.    tallen@fsc.fujitsu.com
"In going on with these experiments, how many pretty systems do we build,
 which we soon find outselves obliged to destroy?" - Benjamin Franklin
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